Asus’ ROG Maximus VIII Impact motherboard reviewed

Mini-ITX motherboards can be found in almost every motherboard manufacturer’s portfolio these days. Asus has several of these small-form-factor boards in its lineup, capped off by its enthusiast-oriented Republic of Gamers (ROG) line. The Impact models are Asus’ Mini-ITX boards for the Republic of Gamers, and the company has updated the concept for for the Z170 platform with its Maximus VIII Impact.

The limited board area of the Mini-ITX standard places tight constraints on what features and functionality can be integrated into these boards, especially for expansion slots. Enthusiast mobos like the Impact only come with one PCI Express expansion slot, and that space will almost certainly be occupied by a graphics card. As a result, it’s important that the board satisfy as many end-user requirements as possible out of the box.

The Maximus VIII Impact keeps with the same basic layout as its predecessors: the Z97 Maximus VII Impact and the Z87 Maximus VI Impact. This is certainly not a bad thing, because the formula obviously works. The biggest difference in aesthetics is that the expansion ports on the Maximus VIII Impact are now clad in muted grays rather than the striking red of previous designs.

Dimensions of only 6.7″ x 6.7″ (17 x 17 cm) leave Mini-ITX boards with less than 40% of the PCB area compared to their full-sized ATX brethren, and half as much as their microATX counterparts. That’s not a lot of room to for onboard components, especially when we’re still dealing with the same LGA 1151 CPU socket and 288-pin DDR4 DIMM slots from those larger motherboards.

To make the most of Mini-ITX’s limited real estate, Asus builds upwards. The best example of this strategy is the daughterboard seen running along the top edge of the board. This houses the Impact’s VRM components.

The Maximus VIII Impact’s daughterboard holds a premium eight-plus-two voltage regulation complex. Digital PWM controllers power eight phases for the CPU and two for the memory. This design should let the Impact hold its own against much larger motherboards in the VRM department. A slim ROG-branded heatsink cools these components. The few VRM components found around the CPU socket feed the processor’s system agent and I/O voltage rails. Just as a reminder, Skylake processors once again rely on the motherboard’s VRM to supply each of the processor’s input voltage rails—the fully-integrated voltage regulator (FIVR) used by previous-generation Haswell chips has fallen out of favor.

Voltage regulation isn’t the only area where we see Asus reaching for the skies. Onboard audio and Wi-Fi also have their own separate riser boards. Those vertical elements are large enough to interfere with CPU coolers that branch out from the socket. This complicates clearances around the CPU socket, which is already closer to the DIMM slots than we’d like.

Here are some measurements showing the distances between the CPU socket and nearby components:

On larger boards, we’re usually most concerned with the proximity of the first PCIe x16 slot to the CPU socket. In the case of the Maximus VIII Impact, it’s the audio riser that’s potentially most troublesome. Thankfully, that riser is only 36 mm tall. The VRM daughterboard is slightly taller, at 42 mm. Those who plan to install big heatsinks that overhang the CPU socket area should check clearances to avoid any nasty surprises.

Tight clearances on the Impact aren’t just a problem for large air coolers. The beefy water block of the Cooler Master Nepton 240M liquid cooler we use for testing runs afoul of the capacitors to the left of the CPU socket. This conflict prevents the block from making sufficient contact with the CPU’s heat spreader, removing two of the four possible orientations as workable options. Clearance issues between the DIMM slots and the hose connections to the block ruled out a third possible orientation. We finally pointed the hose side of the water block toward the I/O ports.

The two DDR4 DIMM slots can hold up to 32GB of memory when they’re filled with 16GB sticks. For single-DIMM configurations, Asus recommends using the slot closest to the CPU socket. To get the best performance, though, you’ll need to fill both slots for dual-channel operation. With the DIMM slots caught between the VRM daughterboard and the PCIe x16 slot, swapping DIMMs is likely going to involve removing the video card first. That said, I’m happy to see two full-sized DIMM slots rather than the SO-DIMM alternative. Asus also uses slots with locking mechanisms on only one end, which makes life a little easier.

The Maximus VIII Impact’s single x16 PCIe slot is fed with sixteen Gen3 lanes coming from the processor. Once the graphics card is installed here, getting to the SATA ports may prove difficult. That problem will only get worse once the board is in your case, so be sure to connect your storage before installing your GPU.

Thanks to Intel’s 22-nm fabrication process, the Z170 chipset has a TDP of only 6W. This allows Asus to get by with the slim heatsink seen directly above the PCIe x16 slot. Immediately to the left of the chipset heatsink we can see Intel’s Alpine Ridge USB 3.1 controller, labeled Intel DSL6540. For the Maximus VIII Impact, Alpine Ridge is acting purely as a USB 3.1 controller with no support for Thunderbolt 3. It is connected to four of the chipset’s Gen3 PCIe lanes, endowing it with 32 Gbps of bandwidth. The tiny Intel chip to the left of the PCIe x16 slot is the I219-V Gigabit Ethernet controller. It connects to a single PCIe lane from the chipset.

Here’s a graphical representation of how the Maximus VIII Impact uses the platform’s PCIe lanes:

Now, on to the Impact’s storage subsystem.


Storage, ports and audio

The Impact’s SATA ports reside in the bottom right corner of the board, between the chipset heatsink and the DIMM slots.

Here we find four standard SATA 6Gbps ports. Given that the board will most likely be installed in small Mini-ITX enclosures, four SATA ports seems ample. Asus decided to eschew any support for SATA Express on the Impact. That omission is no great loss, considering how few drives on the market support the standard. Instead, the Maximus VIII Impact puts all its next-gen storage eggs in the NVMe basket with a single U.2 connector on the other side of the board.

The U.2 connector is normally sandwiched between the Wi-Fi card and the audio riser. Removing the SupremeFX audio card, we get a much better look at this next-gen storage goodness. PCIe SSDs connected via this interface, like Intel’s 750 Series SSD, get four Gen3 lanes from the chipset. Those lanes give PCIe storage devices up to 32 Gb/s (4 GB/s) of bandwidth, an impressive increase over their SATA-based counterparts.

Despite the board space it saves, the U.2 connector is a bit of an odd duck in the world of storage devices right now. It would have been nice if the Maximus VIII Impact came bundled with a U.2 to an M.2 adapter so that owners could use more common M.2 PCIe SSDs in the near term. U.2 devices are often 2.5″ SSDs that need bulky cabling and a dedicated drive bay. Both of those demands can be liabilities in Mini-ITX cases, and gumstick M.2 SSDs sidestep them entirely.

A welcome side effect of the limited expansion options forced by the Impact’s diminutive board dimensions is that there are no pesky “sharing” rules that place restrictions on which storage ports can be used simultaneously. What you see is what you get.

With the audio riser removed, we can also see the board’s eight voltage monitoring points below the U.2 connector. Asus’ engineers are using almost every square millimeter of board real estate. Hopefully those who would use these voltage monitoring points aren’t going to be needing audio.

Just to the right of the U.2 connector we can see the Impact’s socketed firmware chip. Slightly above and to the right is a two-pin header that connects to the CMOS battery. Previous iterations of the Impact board had the CMOS battery mounted vertically on the board’s surface. Presumably, moving the CMOS battery off the board itself freed up valuable PCB space for other components. Once again, it’s impressive how much functionality Asus crammed into just under 45 square inches.

One area where the Maximus VIII Impact has been forced to go on a diet is in the fan header department. The board itself supports just two fan headers: one CPU, and one system. Enthusiast-class Mini-ITX systems often require more than just one system fan header, though. To solve this problem, Asus bundles one of its fan extension cards with the board.

This extension module connects to the EXT_FAN header on the top-left corner of the Impact, and it provides three more four-pin fan headers and three more connectors for standard temperature probes. Thermistors attached to the fan module supply reference temperatures to the fan control intelligence managed by the board’s firmware and utility software. This bumps the number of temperature-controlled fan headers that the board can support to five. A very respectable number, even by full-sized ATX standards.

The Maximus VIII Impact’s rear port cluster is part control panel, part I/O. Starting at the left, we have S/PDIF audio output. This port passes a pristine digital signal to compatible speakers and receivers, neatly bypassing the pitfalls associated with onboard analog audio. The digital out natively supports stereo playback and surround-sound sources like movies with pre-encoded tracks. Bundled DTS Connect software adds on-the-fly encoding for multi-channel output, allowing surround-sound game audio to be piped through the S/PDIF out, as well.

For tapping into Skylake’s integrated GPU, the Impact offers a single HDMI 1.4b connector, thanks to an ASMedia ASM1442K level shifter. Folks with discrete graphics cards don’t have to concern themselves with the onboard display outputs, of course.

A small vertical riser provides a handful of buttons and a two-digit diagnostic display. Asus calls this the Impact Control module. The top-most square button restores firmware defaults. The square button below is for Asus’ USB BIOS Flashback feature. The orange button powers on the system, while the black one resets it. Having these functions accessible outside the case is a huge bonus for Mini-ITX systems, whose internals are often too crowded to poke around inside easily.

 A stack of four USB 3.0 ports, in blue, are connected directly to the chipset. The Impact also provides two more USB 3.0 ports from an internal header. The bottom-most port is the one that you’ll need to connect your keyboard to in order to use Asus’ KeyBot functionality. KeyBot allows you to configure and assign macros to specific keys and pre-record sequences of characters for immediate play back on a single key press. You can also assign hotkeys for tasks like powering on, clearing the CMOS, booting directly to the firmware, and more. The KeyBot software works in conjunction with onboard hardware to make this possible.

The USB 3.0 port second from the bottom is used for the USB BIOS Flashback functionality. This feature lets one update the firmware with nothing more than a USB thumb drive and a power supply. Although it’s not a feature you’ll use every day, BIOS Flashback could save you from having to beg, borrow, or steal a supported CPU to flash the firmware for a newer chip.

To the right of the USB 3.0 port stack are the connectors for the wireless antenna. Wi-Fi connectivity is provided by a Qualcomm Atheros QCA61x4A 802.11ac controller with a 2×2 antenna and dual-band support for 2.4GHz and 5GHz networks alike. This chip supports Multi-User MIMO (MU-MIMO) and Bluetooth 4.1. The Wi-Fi adapter itself is an M.2 2230 card that connects to the board with a vertical M.2 slot adjacent to the USB stack.

The Gigabit Ethernet port is powered by Intel’s I219-V controller. Below this port are USB 3.1 Type-A and Type-C ports, powered by the onboard Alpine Ridge USB controller.

We generally expect motherboard makers to ship a cushioned I/O shield with their high-end products, and Asus doesn’t disappoint on this front. In the Impact’s box, we get a nicely cushioned I/O shield. Our Band-Aids can safely stay in the medicine cabinet today.

After all those words, it’s time to break out the crayons for a graphical representation of the Maximus VIII Impact’s port cluster:

Similar to previous Maximus Impact boards, analog audio is handled on an entirely separate audio riser, which Asus calls the “SupremeFX Impact III.” This card gets the sensitive analog signals and components off the main PCB, away from the electrically noisy environment below. EMI shielding around the audio board could help matters even more. The SupremeFX Impact III is something of a hybrid between a discrete sound card and a more traditional integrated audio implementation, where all the components are on the motherboard PCB.

Those three audio jacks have a little something extra up their sleeves. Each one is back-lit with a different colored LED: red for microphone in, green for line out, and blue for line-in. This can help you identify which output is which in the dark. It also looks pretty cool.

At the heart of the Impact’s audio implementation is Realtek’s familiar ALC1150 codec, backed up by premium audio components. Moving left, we can see high-end Nichicon SW series capacitors, an ESS Sabre ES9023P DAC, a Texas Instruments RC4580 headphone amplifier, a dedicated high-precision clock generator, and an NEC de-pop relay. The headphone amp is rated for headphones up to 600 ohms, and it automatically detects headphone impedance. That should cover most common audio headgear.

This audio hardware is paired with Asus’ own Sonic Studio and Sonic Radar software. Sonic Studio is similar to the Nahimic software that we looked at in the MSI Z170A Gaming M5 review. It provides virtual surround support, a handful of tunable audio effects and an equalizer, as well as some default profiles for music, movies, and gaming.

Sonic Studio also has options for tuning incoming and outgoing microphone feeds, and it can route a recording or streaming session through its software stack.

Sonic Radar is an Asus-developed application that provides a visual representation of surround-sound game audio. It provides an overlay that shows the direction in-game sounds are coming from. The overlay itself is highly configurable with adjustable opacity, size, and positioning.

Sonic Radar’s different filtering modes allow you to focus on specific kinds of sounds: gunshots, explosions, voices, etc. Settings can be toggled using either the application itself, or via hotkeys.

My ears were happy during our audio testing. The analog output didn’t produce any unwanted feedback or noise with the system at idle or under load. That’s a good thing, because we’d have to resort to a USB sound card or another external solution if the Impact’s onboard audio wasn’t up to snuff.



The Maximus VIII Impact’s firmware is almost identical to the firmware on Asus’ other Z170 boards. It’s been given a once over with the Republic of Gamers paint brush, though.

One other obvious difference is that the first time you enter the firmware you’ll land in the Advanced Interface:

You can still use the EZ Mode interface by swapping to it using the F7 key, or by setting it as the default interface that appears when you enter the firmware.

Given the board’s target market of gamers and tweakers, I think it makes sense to default to the Advanced Mode interface. That is most likely where most users will spend the bulk of their time. The Republic of Gamers treatment means that the cool blue tones of the channel boards’ interfaces have been replaced with ROG-style red.

Rather than rehash what we’ve already covered in the Z170-A review, I’ll instead pull out a couple of the high points.

Let’s start with fan controls. The firmware’s fan control are full-featured and offer the same options as the board’s Windows software. There’s a built-in calibration routine to determine the exact speed range of each connected fan. Four pre-baked fan curves complement a manual mode that allows the creation of fan response profiles by simply moving three points on a graph of temperature and fan speeds. If you don’t want to install the Windows utilities—or you’re not running Windows—you still have complete control over your system’s fans.

The fan control logic works with both three-pin DC and four-pin PWM fans, and it gives you complete control over both the two onboard headers, as well as the three on the fan extension card.

The temperature source that is used to govern the fan speed for the system fan header and the three fan extension card headers can be the CPU, motherboard, chipset, the temperature probe connected directly to the motherboard, or one of the three temperature probes connected to the extension card. This offers a great deal of flexibility in managing the system’s thermals.

What once would have seemed like science fiction—motherboard firmware that can connect to Asus’ servers, download the latest UEFI update, and flash your board all by itself—is now available to us all. This Internet awareness takes the hassle out of updates, and it reminds me just how far we’ve come.

If there is one complaint that could be made about the Impact’s firmware, it’s that the interface is rendered at only 1024×768. That said, the GUI still looks great, even if the text and graphics aren’t quite as crisp as  firmware interfaces sporting 1080p resolutions.


Just as with its firmware, the Maximus VIII Impact’s suite of tweaking software carries over from Asus’ other Z170 boards with a fresh coat of ROG paint.

As we’ve come to expect, Asus’ AI Suite is loaded with tweaking options for everything from multipliers and clock speeds to voltages and power controls. Most variables can be altered either by dragging mouse-friendly sliders around or by keying in values directly.

AI Suite’s Fan Xpert 3 function provides extensive fan speed controls similar to what’s available in the firmware. We’ve consistently been impressed with the quality of Asus’ software fan controls, and AI Suite doesn’t mess with success on this point.

By far one of the most impressive components of AI Suite is the auto-tuning wizard. This software-based wizard has more power than its firmware-based counterpart.

Not only does this wizard scale up clock speeds iteratively and test stability at each step, just like an enthusiast would, it’s also highly configurable. You can set temperature thresholds, voltage limits, and the frequency at which to start testing—either stock speeds or something higher. There are even configurable options for the duration and nature of the stress test. Do you want to include memory stress tests? How about an AVX workout to really stress those vector units? With a few simple mouse clicks, Asus’ helpful little overclocking minion sets off to do your bidding.

Saved profiles can be loaded manually or via the Asus Turbo App feature, which invokes them automatically based on application-specific preferences. Individual apps can be tied to a combination of performance, fan, audio, and networking profiles. The audio and networking settings are fairly simplistic compared to the other profiles, but they make Turbo App more of a full-fledged system tuner than a selective overclocker.

When it comes to tweaking memory timings from within Windows, Asus’ MemTweakIt utility should be your first stop. If there’s a knob that can be tuned in Skylake’s memory controller, you’ll probably find a corresponding dial buried in one of the timing options tabs.

Another useful little tool is the boot settings utility. It provides a quick shortcut to enter the firmware, without having to resort to mashing the delete key furiously on a reboot. In the age of fast boot, these are handy settings to have.

Asus also ships two RAM-based utilities with the Impact: RAMDisk and RAMCache. RAMDisk, as its name suggests, lets you carve off a portion of your system memory for use as a drive. RAMCache, on the other hand, allocates a chunk of your RAM to use as a cache for secondary storage, either solid state or spinning disk. These tools may be appealing to folks with an abundance of memory, but it’s important to keep in mind DRAM’s volatile nature—if you lose system power, the contents of your RAM disk or cache will be lost.

That’s enough time kicking the tires. Let’s take the Maximus VIII Impact for an overclocking spin.



A given processor’s top stable frequency is mostly determined by the limitations of that particular chip—also known as the silicon lottery—and the CPU cooler one straps on top. Still, whether your particular CPU is the golden child of the wafer or the runt of the litter, you want a motherboard that makes the process of finding out as painless as possible.

We tested the Maximus VIII Impact’s overclocking chops using a Core i7-6700K CPU with Cooler Master Nepton’s 240M strapped on top. The Nepton has a 240-mm radiator that can put a ton of cooling power in Mini-ITX cases where big tower heatsinks just can’t go, so it actually makes a fair bit of sense to pair it with the Impact. This liquid cooler should do a good job of keeping our four Skylake cores from getting too toasty.

First up, we gave the firmware’s EZ Tuning Wizard a shot. After letting it know that we were after an overclock for our gaming and encoding tasks, and that we had an all-in-one liquid cooler, the wizard boosted clocks to just over 4.6GHz using a 45X multiplier and a 103MHz base clock. To support these speeds, the firmware supplied the CPU with 1.456V. This config resulted in thermal throttling during our Prime95 stress test. The i7-6700K’s temperatures rose to 98°C within seconds. I was curious to see whether a less demanding workload would be stable, so I fired up Cinebench and kicked off its multithreaded CPU rendering test. That task completed successfully with no signs of thermal throttling, and CPU temperatures topped out at 76°C.

AI Suite’s auto-tuner was next. We configured it to start from the CPU’s default ratio and enabled the software’s AVX testing and its memory stress test. After the process finished, AI Suite settled on a 46X Turbo multiplier for 1-2 core loads and 44X with 3-4 cores engaged, on a slightly boosted base clock of 100.7MHz. Our chip was perfectly stable during our Prime95 stress test, which pegged it at 4.4GHz and 1.392V. Package temperatures reached 73°C, and we saw no signs of throttling.

With all of the automated overclock testing out of the way, we moved on to manual tweaking through the firmware. Using multipliers alone, with the voltages on their “auto” defaults, we made it all the way to a stable 4.6GHz. At this speed, the firmware supplied 1.408V to the CPU, and temperatures maxed out at 76°C under our Prime95 load.

While a stable 4.6GHz clock speed was firmly within our grasp, pushing any higher was unsuccessful. When we set a 47X multiplier, the firmware dialed in a voltage of 1.424V for us. This gave us BSODs within minutes of starting the Prime95 stress test. Increasing the core voltage manually saved us from that BSOD, but ultimately one of our worker threads would encounter errors. Pushing the voltage any further caused thermal throttling step in to quash our dreams of higher speeds.

Our journey ended with a very respectable overclock of 4.6GHz, which is only 100MHz less than the highest we’ve ever managed to achieve with this particular Core i7-6700K and Nepton 240M cooler. Our Maximus VIII Impact can certainly keep up with the competition when it comes to overclocking.

Z170-based boards feature a revised reference clock architecture that decouples the PCIe and DMI bus speeds from the base clock. This setup gets base clock overclocking back in the game because it allows one to tweak the base clock without having to worry about running other system devices out of spec. As a quick test, we set the base clock to 200MHz in the firmware and left everything else on “auto.” The system booted perfectly, and our CPU was stable at 4.4GHz:

With a 200MHz base clock conquered, we were hungry for more. Bumping up the base clock in 33MHz increments, we got all the way to 266MHz:

To get us here, the firmware lowered the core multiplier to 17X, and it ran the uncore in sync with the cores. On the memory front, we had to first select our XMP profile and dial up the base clock before decreasing the memory multiplier. This approach let us keep our DIMMs humming along around 3000 MT/s. This config worked perfectly, and we were stable at just over 4.5GHz.

Pushing the base clock to 300MHz had the firmware drop the core multiplier to 16X. At 4.8GHz, we could boot into Windows, but our 6700K wasn’t able to pass our Prime95 stress test. Attempting to lower the core multiplier to 15X left to the system in a state where it wouldn’t even POST. Still, a 266MHz base clock tweak is impressive.

Overclocking our Skylake chip on the Maximus VIII Impact was a very smooth process. Not only was tweaking clock speeds a breeze in Asus’ firmware, but the auto-tuners in the firmware and AI Suite were easy-to-use, one-click solutions that gave good results. Auto-tuning solutions like these can be very beneficial for newbies as they get started with overclocking, and as a starting point for more seasoned tweakers. I’m constantly impressed by the configurability of the software-based auto-tuner.

Now that we’ve had our fun tweaking, let’s see how the Impact’s performance stacks up.


Performance highlights

Since many traditional chipset functions now reside on the CPU die and there’s only a handful of third-party peripheral controllers out there these days, we rarely see meaningful performance differences between motherboards anymore. That said, we still test system performance when we review motherboards to ensure everything is functioning correctly.

When it comes to testing motherboard performance, we’ve usually gathered benchmark results using the CPU’s peak stock memory multipliers. Since DDR4 is so new, however, and Skylake’s 2133MHz maximum stock DDR4 speed is so conservative, we’ve continued a practice we began with our X99 reviews. We test our Z170 boards with the memory clocked at the highest XMP profile speed we can attain while keeping the CPU at its stock clocks.

We tested the Maximus VIII Impact against Asus’ own Z170-A, Gigabyte’s Z170X-Gaming 7 and Z170X-Gaming G1, and MSI’s Z170A Gaming M5. All the boards were able to keep our DDR4 DIMMs clocking along at 3000 MT/s while maintaining stock CPU clocks, so the results below were gathered with these settings.

Asus’ Maximus VIII Impact consistently places at or near the top in the majority of our benchmarks. The only exception is the Sunspider javascript benchmark. This test has a run-to-run variance that’s approximately the size of the spread of results, so we shouldn’t put too much weight on this. The only other test where we see the Impact end up at the bottom of the ranks is the x264 encoding test, but it is only 2.2% slower than the leader.

When we power on the Impact, it boots slower than the speediest contender by over six seconds. Modern systems have perfectly functional sleep and hibernate modes that can mitigate these boot times, though, so we don’t think the lengthy boot time is anything to worry about.

Power consumption

While one’s choice of motherboard might not affect performance much, it can have a notable impact on power consumption. We measured total system power draw (sans monitor and speakers) at the wall socket for five minutes of idle time at the Windows desktop. We then repeated the test under a full load of Cinebench rendering with the Unigine Valley demo running at the same time.

The Maximus VIII Impact has the lowest power consumption under load, but it ends up in the middle of the pack under idle conditions. The most interesting result is that under load, the Impact manages to shave off 7W of power when Asus’ EPU power-saving feature is enabled. This is a larger power savings than we’ve seen from previous Asus boards, including the Z170-A.

The following page is loaded with detailed motherboard specifications, system configurations, and test procedures. If you’re having trouble getting to sleep—or you just really love tables filled with data—feel free to peruse. For those who jump straight to the conclusion, my lips are sealed.


Detailed specifications

We’ve already gone over the Maximus VIII Impact’s most important details, but for completeness, here’s the full spec breakdown.

Platform Intel Z170, socket LGA1151
DIMM slots 2 DDR4, 32GB max
Expansion slots 1 PCIe 3.0 x16 via CPU
Storage I/O 4 SATA RAID 6Gbps via Z170

1 U.2 via Z170 (PCIe 3.0 x4 NVMe)

Audio 5.1-channel HD via Realtek ALC1150 with ESS Sabre ES9023P DAC

Real-time digital encoding via DTS Connect

Asus Sonic Studio and Sonic Radar

Wireless Qualcomm Atheros QCA61x4A 802.11ac 2×2 dual band 2.4/5 GHz supporting MU-MIMO

Qualcomm Atheros Bluetooth 4.1

Ports 1 HDMI 1.4b via CPU

2 USB 3.1 (1 Type A and 1 Type C) via Intel Alpine Ridge controller

4 USB 3.0 via Z170

2 USB 3.0 via internal header and Z170

1 Gigabit Ethernet via Intel I219V

3 configurable analog ports (front, center, rear, mic, headphone, line in)

1 digital S/PDIF output

Overclocking All/per-core Turbo multiplier: 8-83X

Base clock: 40-650MHz

Min. CPU cache ratio: 8-83X

Max. CPU cache ratio: 8-83X

Base:DRAM ratio: 100:133, 100:100

DRAM clock: 800-4266MHz

CPU voltage: 0.6-1.7V

CPU VCCIO voltage: 0.7-1.8V

CPU system agent voltage: 0.7-1.8V

CPU standby voltage: 0.8-1.8V

PLL termination voltage: 0.36-2.1V

DRAM voltage: 1.0-2.0V

DRAM CTRL ref. voltage: 0.395-0.63V

DRAM DATA ref voltage A, B: 0-0.63V

DMI Voltage: 0.3-1.9V

PCH core voltage: 0.7-1.8V

LN2 mode jumper

Slow mode jumper

Probelt voltage measurement points

Fan control 1 x CPU (DC and PWM), 1 x SYS (DC and PWM), 3 x SYS via fan extension card (DC and PWM)

Predefined silent, standard, and turbo  speed profiles

Manual profile with three temp/speed points per fan

Our testing methods

As a reward for making it this far, you may now gaze upon our test system:

Performance testing and overclocking were carried out on an open-air testbed.

We used the following configurations for testing:

Processor Intel Core i7-6700K
Cooler Cooler Master Nepton 240M
Motherboard Asus ROG Maximus VIII Impact Gigabyte Z170X-Gaming G1 Gigabyte Z170X-Gaming 7 MSI Z170A Gaming M5 Asus Z170-A
Firmware 1302 F4 F5e 1.20 0601
Platform hub Intel Z170
Chipset drivers 10.1.1
Audio SupremeFX Impact III (ALC1150) Creative Sound Core3D (CA0132) Creative Sound Core3D (CA0132) Realtek ALC1150 Realtek ALC892
Memory size 8GB (2 DIMMs)
Memory type Corsair Vengeance LPX DDR4 SDRAM at 3000MHz
Memory timings 16-18-18-39-2T
Graphics Sapphire Radeon HD 7950 Boost with Catalyst 15.7 drivers
Storage OCZ ARC 100 120GB
Power Supply Cooler Master V750 Semi-Modular
Operating System Microsoft Windows 8.1 Pro x64

Thanks to Antec, Cooler Master, Corsair, and OCZ for providing the hardware used in our test systems. Our thanks to the motherboard makers for providing the boards, too.

We used the following versions of our test applications:

Some further notes on our test methods:

  • All testing was conducted with motherboard power-saving options enabled. These features can sometimes lead to slightly slower performance, particularly in peripheral tests that don’t cause the CPU to kick into high gear. We’d rather get a sense of motherboard performance with real-world configurations, though; we’re not as interested in comparing contrived setups with popular features disabled.
  • DiRT Showdown was tested with ultra detail settings, 4X MSAA, and a 1920×1200 display resolution. We used Fraps to log a 60-second snippet of gameplay from the demo’s first race. To offset the fact that our gameplay sequence can’t be repeated exactly, we ran this test five times on each system.
  • Power consumption was measured at the wall socket for the complete system, sans monitor and speakers, using a Watts Up Pro power meter. The full-load test combined Cinebench’s multithreaded CPU rendering test with the Unigine Valley DirectX 11 demo, which we ran with extreme settings in a 1280×720 window. We then recorded the peak power consumption during the Cinebench run. Our idle measurement represents the low over a five-minute period sitting at the Windows desktop.
  • Our system build was performed using all of the hardware components listed in the configuration table above. Completing this process as our readers would allows us to easily identify any pain points that arise from assembling a system with this particular motherboard.

The tests and methods we employed are publicly available and reproducible. All tests except power consumption, were run at least three times. Unless otherwise indicated, we reported the median result for each test. If you have questions about our methods, hit our forums to talk with us about them.



The Maximus VIII Impact is the third generation of Mini-ITX motherboards from Asus’ premium Republic of Gamers family. Since the first Impact board came out, Asus has been busy refining its formula for a premium small-form-factor board. At $250 online, the Impact is the most expensive Mini-ITX LGA 1151 board on the market right now, more expensive than a lot of premium ATX boards. That price sets the bar quite high for this mobo. We’re happy to report that the Impact delivers, though, aside from one minor complaint.

We do wish Asus had found room for an M.2 slot on the Maximus VIII Impact. The included U.2 connector may save board space, but few next-gen storage devices can plug into this connector right now. To be fair, there are worse things in life than being stuck with Intel’s 750 Series SSD, but the U.2 version of that drive needs a bulky combo cable for power and data, as well as a dedicated drive bay. Those space requirements could be a liability in tiny Mini-ITX cases, and M.2 gumstick SSDs neatly avoid them. Gigabyte’s GA-Z170N-Gaming 5 motherboard hides an M.2 slot on its back side, so the feature isn’t unprecedented on Mini-ITX mobos.

Despite that one hitch, the Impact still packs some impressive hardware into a tiny board. We get USB 3.1 courtesy of Intel’s Alpine Ridge controller, a VRM array that wouldn’t be out of place on a high-end ATX board, an impressive onboard audio implementation, built-in Wi-Fi, and more. Performance is right up there with full-size ATX boards, too. The hardware itself is backed up with Asus’ excellent firmware and software. The firmware and Windows utilities are friendly enough for newbies to get the most out of them while presenting enough knobs and sliders to keep even the most die-hard tweakers happy.

On the overclocking front, the Impact got our Core i7-6700K to within 100MHz of the best overclocking results we’ve achieved on any board. It’s also no slouch when it comes to base clock overclocking, with a stable speed of 266MHz. It’s nice to know that if you opt to build a Mini-ITX system with the Impact, the board won’t be the limiting factor for overclocking.

Asus’ fan control suite remains the best in the business. The Impact offers one of the most comprehensive fan control setups we’ve seen on a Mini-ITX board, too. Its included fan riser card lets system builders take full control of system fans in Mini-ITX cases without resorting to annoying stopgaps like fan splitters or manual fan controllers. Little touches like the power buttons and diagnostic display in the rear port cluster, along with the cushioned I/O shield, make building a small system with the Impact that much more pleasant, too.

Overall, it’s impressive how much good stuff Asus has crammed into such a small motherboard. If you’re in the market for a premium Z170 board for Mini-ITX systems, the Maximus VIII Impact would be an excellent choice to build your small system around.

Comments closed
    • Legolas1080
    • 7 years ago

    I heard from Asus that the Maximus VIII Impact has U.2 slot now. Very cool!

    • Chrispy_
    • 7 years ago

    I loathe daughterboards on mITX motherboards.

    If you truly need the overclocking ability provided by the extra power phases on the daughterboard, you’re being an idiot for choosing an mITX motherboard. For a start, you’re going to need a big case to accommodate the full-size PSU and 240mm or larger radiator(s). Yes, there are a handful of mITX cases that fit the bill, but they’re also larger than most mATX cases and several full ATX cases, at which point their reason for existing is “gimmick”.

    • ajira99
    • 7 years ago

    Yep, I got a new M.2 SSD on my Z97I-Plus in an Ncase M1. It’s very easy to access the SSD on the back of the motherboard (just don’t lose the standoff or mounting screw!). The Carbide Air 240 is pretty similar although you have to remove the hard drive cage.

    • bhtooefr
    • 7 years ago

    Mind you, the ASRock X99E-ITX/ac actually managed to cram a M.2 slot on the [i<]front[/i<]... along with a (Narrow ILM, but still) LGA2011-3 socket. But, then, it doesn't have as many features as the Maximus VIII Impact - it's basically, here's your LGA2011-3 socket, here's two DIMM slots (you don't even get quad channel, no room for it), enjoy.

    • bhtooefr
    • 7 years ago

    In fact, there’s already at least one case with a suitable cutout – I can get at my GA-Z170N-Gaming 5’s M.2 slot by just pulling off the left side panel on my NCASE M1. It literally takes me a second to get to the slot, it’s probably the easiest component in the entire case to get at (the optical drive is easy to get to but has more, smaller screws, and the 2.5″ SSD is easy to get to but requires reaching down through the top, or pulling the fan bracket off).

    Now, the real problem is if U.2 takes off, because there’s not enough clearance for a M.2 to U.2 adapter using a Mini-SAS connector. There’d be other ways to do such an adapter, though, that would be lower profile.

    • Shinare
    • 7 years ago

    [quote<]Overall, it's impressive how much good stuff Asus has crammed into such a small motherboard.[/quote<] Does it really count as "crammed in" if it utilizes two daughterboards that together look to make up atleast %25-50 of the mainboard's area?

    • spugm1r3
    • 7 years ago

    [quote<]Can they be mounted vertically?[/quote<] Again, it's a space concern. Even when you find enough real estate on the top of the board, not already occupied by an IC of some sort, it's probably housing traces for the processor or the memory. That means a board maker has to get even more creative with their traces, which need to be of specific lengths and pairings, or add more layers to the PCB, which increases costs. I get the hesitation, but your only other option is to voice your concerns to the case makers and be a slave to the speed of business.

    • JustAnEngineer
    • 7 years ago

    It’s the EVGA 06G-P4-4992-KR.

    • slowriot
    • 7 years ago

    Goes with my experience as well.

    I’m curious…. what graphics card do you have? And when you use it in the most demanding game you have what temperature does it maintain?

    • JustAnEngineer
    • 7 years ago

    I started a small list of cases in this forum thread:
    [url<][/url<] The [url=<]Fortress FTZ01[/url<] is the aluminum version of the plastic [url=<]Milo ML07[/url<], which is a more conservative version of the [url=<]Raven RVZ01[/url<]. You can see a list of components in my forum signature. My graphics card pulls three times as much power as my CPU does when I am playing a game. Nevertheless, this same graphics card with Haswell in the micro-ATX case was quieter than it is now with Skylake in mini-ITX.

    • slowriot
    • 7 years ago

    Which high end ports are you talking about? I don’t want more video outs. It’s useless. It should have another NIC and at least one more full bank of USB ports. It should also have a PS/2 so I can plug my Model M keyboard in.

    Your definition of necessary ports for a high end motherboard is arbitrary. It doesn’t represent the buyer of this product. You continually fail to realize this.

    The motherboard you’re looking for costs $120-$170 at most. This one isn’t for you. Why is this so hard? Products are not made in the make believe world you’re trying to judge them in.

    • slowriot
    • 7 years ago

    Why include video outputs at all? I rather the entire back use that space for more USB options. I wouldn’t mind a second set of USB 3.1 ports. Why not also include two NICs? Once I finish using this in my beast HTPC and retire it to my desktop I also want it to be a NAS and a home render server. I need dual NICs and also I’d like for it to connect to an external array with USB 3.1 because I’m going to put it inside one of those VESA mountable cases. It’s mini-ITX after all!

    Do you understand? Why not include more than one video out from the IGP? Because no one actually considering a $250 mITX extreme overclocking board is going to use more than one. And likely only in case of an emergency. That’s why. We can play the “Why didn’t they include X in this expensive motherboard” game all day. The only thing you’re even whining about is something specific to your made up scenario, not even something that likely more of the target audience want.

    Seriously. There are other motherboards out there that fulfill your needs. This done doesn’t. Move on.

    • slowriot
    • 7 years ago

    I’m sure the case(s} fans are silent. I’d expect them under load to be the quietest fans in your system. It’s the GPU fans, the CPU fan, the PSU fan or heck even a mechanical hard drive that has me wondering what you mean by “silent.” For instance, in just the past couple weeks I’ve seen multiple claims of silence from people who have components that I’ve used and KNOW are not and yet… they label them has such. So, it’s not to say you’re lying, but to say… your “silent” probably isn’t my “silent.”

    As far as the M1… no I don’t own it. I’ve used a friends revision 3, but haven’t seen a new V5 in person. Personally I’ve moved away from mITX after using it as the platform for my workstation/gaming systems since 2009. Now primarily this is because I’m very likely going dual GPU once VR starts arriving in force. But also because after trying out 3 different mITX cases this time around I just had it with the noise levels under load.

    I just built a new system inside an NZXT S340. It’s quite compact for an ATX mid tower (as small as most of the popular mATX options) because I didn’t want to go huge, but it provides a lot more options for cooling and therefore quiet. As in nothing but speed reduced Noctua’s and a water pump surrounded by sound dampening foam. But I did this after going thru a Lian Li TU200, Phanteks Evolv ITX, and Silverstone’s SG13 and RVZ02…. thank you Amazon return policy.

    A note on SFX PSUs… I haven’t used an SFX since I had an SG05 way back. THat case was definitely loud, but we’re talking 2009. Recently with the RVZ02 I tried a new Silverstone SFX-L 500W PSU and that produced audible coil whine sounding noise when at idle. Which was made very obvious because its fan didn’t spin at idle, by design.

    • libradude
    • 7 years ago

    Interesting… I will consider myself lucky then, I guess – I just have not had that experience with mine. Under gaming load, I can usually hear the fan(s) on the video cards get louder based on the profiles I’ve set, but the case fans themselves are inaudible from ~4 feet away.

    Do you have an NCase M1? I looked long and hard at those but wanted to get away from the SFX power supply. I know it supports an ATX psu but I couldn’t go that route due to a longer video card. They do look really nice, but I spent about the same amount on the SG08 which came with a 600w psu. I realize the M1 is aluminum and that will cause the price to be more than a steel case, but I’ve had good luck with Silverstone so figured I would stay with them for now.

    I agree that we need more innovation in small ITX cases! I have built a system in the Corsair 250D for a friend and really liked it, but it’s just too big for my preference.

    • slowriot
    • 7 years ago

    I’m always left with a confused face when someone claims these cases are “virtually silent.” If by “virtually silent” you mean fairly loud. The SFX PSUs alone get annoying under load in a SG05. Part of the reason Silverstone has their SFX-L PSUs is because people found the fans in the SFX units annoying. Even the SG08 with its perforated side panel on the GPU is setting you up to get blasted by that fan when it spins up.

    I’ve yet to find a quiet mini-ITX case that wouldn’t be considered over-sized besides the NCase M1.

    I’ve tried a lot of them, btw. Tower and cube styles.

    • libradude
    • 7 years ago

    Thanks for the info, JAE – I have two Sugo SG05s (300w and 450w variants) and just built a new system in an SG08, so I have no experience with the Fortress series – but after looking at the pics on Silverstone’s site, I would be hesitant to try to build in that case too.

    I can say that the SG05s and SG08 are virtually silent, given their 120mm and 180mm fans, respectively. So I’m guessing there must have been a reason (very long video card? liquid cooling?) as to why you went with the Fortress instead of the Sugo? I fit a 10.5″ 660ti in my SG05 but had to upgrade to the SG08 to fit a reference cooler 970. I do like that the SG08 has an ATX psu, no more SFX – and their “air penetrator” fan is amazing.

    If you have a hankering to build another mITX in the future, I’d recommend more of the toaster shaped cases instead of the slim towers, and I think your experience would be much better than this time. Just my .02!

    • Freon
    • 7 years ago

    You *really* gotta be in love with a tiny bit of airspace savings to want to buy one of these.

    I still don’t get it. Do you live in a shoe box? Do you *really* transport your uberclocked $2k gaming PC on such a regular basis than the form factor is that important?

    • slowriot
    • 7 years ago

    And you will be choosing the $250, overclocking and gaming focused mITX board? Not one of the dozen plus other cheaper and besides the power daughter board…. equally as well featured? If not more so options?

    See, that just makes no sense. Hence the downvotes to the OP. It’s a use that that’s a niche for a board that’s a niche… of a freaking niche. i.e. you’re either ignorant of the other better mITX options for your scenario or for some reason you’re desperately wanting to part with $250 for features you won’t use.

    • slowriot
    • 7 years ago

    How this could be allowed? Is there some kind of motherboard task force?

    How about…. it’s the only way it’s possible. Putting it on the top likely wasn’t an option. So either leave it out or put it on the bottom.

    It drives me crazy that you want to make this out as if designers/engineers here are stupid and didn’t consider other options. They put them up top on larger boards with more room. Chances are highly likely this wasn’t done to piss you off, but rather just a physical limitation.

    • slowriot
    • 7 years ago

    I swear you guys are acting like this is the only mini-ITX Z170 board. It’s not. If what you want isn’t provided by this board go look elsewhere.

    Not every motherboard must fit every use case. There are other options available for your needs…………………..

    • Pez
    • 7 years ago

    Thanks for the review, next build is definitely going to be mITX and was hoping you’d review this 🙂


    • spugm1r3
    • 7 years ago

    Largely, it’s a space concern. I wouldn’t be surprised, if m.2 wins out for consumer systems, that mITX cases would start to come with cut-outs on the motherboard tray for easy swapping. Remember, there was a time when a cutout for swapping your CPU heatsink was uncommon as well.

    Regardless, the fix is relatively simple on the short-term, for those with some imagination and a Dremel.

    • Luay
    • 7 years ago

    I am thinking of building a high-end mitx rig in the new Lian Li PC-Q10. That case has two 120 mm fan mounts on the top and it looks like the air from them will blocked by that sound card on the top of the Impact. That path is critical for supplying air to the PSU and CPU.

    I think the Asrock Fatal1ty Gaming ITX for $175 offers everything the Maximus does plus the M.2 slot and minus the soundcard, which almost always should be external if quality is what you’re after. Currently I’m trying to decide between the pricey Chord Mojo or the portable Audio Quest Dragonfly. Maybe the impact is made for those large ITX cases but I think Asus made a bad judgement.

    • aceuk
    • 7 years ago

    Asus’ Z170I Pro Gaming mITX Skylake motherboard does too, which makes the omission on the Impact even more surprising. The Pro Gaming motherboard is cheaper too!


    • BIF
    • 7 years ago


    You have to remove the motherboard to upgrade the M.2 SSD?

    I’m making cartoon sounds right now trying to understand how this could be allowed?

    • BIF
    • 7 years ago

    I share your concern and that’s why I still have an under-desk tower.

    • BIF
    • 7 years ago

    Well, I agree with you and I don’t quite understand why you got downvoted. ROG equipment makes for computers suited for more than just games. The best audio workstations and graphic workstations have components that also happen to make for good gaming machines.

    Besides that, at this price point, there should have been no fewer than 1 DisplayPort output included for those of us who have/want to use the DisplayPort inputs on our more and more high-quality IPS monitors. Yes, even for gaming.

    You can even buy IPS monitors at Best Buy, Walmart, and from that guy selling rugs from his rusty old van in the abandoned car dealer lot on the corner.

    It befuddles me that Asus would not include DisplayPort ports in their motherboards tattooed with “Republic of Gamers”. When I see decisions such as this, I worry that Asus may be willing to water down the ROG name. That would be a terrible thing.

    • floodo1
    • 7 years ago

    Looks like the Impact series just keeps getting better! I’ll never go back to full size atx after having gone mini-its with last generations Maximis Impact VII and broadwell (-8

    • loophole
    • 7 years ago

    Honestly, for my personal systems I still prefer full-sized ATX boards. I’m far too big a fan of having copious numbers of DIMM slots and PCIe lanes 😉 I have been building more and more systems for friends and family with microATX boards though.

    If I had to build a tiny powerful system for someone with deep pockets this would definitely be my go to board.

    • loophole
    • 7 years ago

    Utter failure on hitting the reply button…

    • JustAnEngineer
    • 7 years ago

    My mini-ITX gaming PC lives in a Fortress FTZ01S. I definitely preferred the micro-ATX Temjin TJ08-E.

    The new mini-ITX system is cute and compact, but the real difference between it and my previous micro-ATX system is that it is much narrower and slightly shallower. They’re about the same height.

    The mini-ITX components were more expensive than similar micro-ATX parts (case, mini-ITX motherboard, low-profile CPU cooler, SFX power supply and especially the slot-load laptop Blu-ray drive). Assembly was not easy. Cooling is worse and it’s noisier than the micro-ATX system. I ran out of USB ports on the mini-ITX motherboard and had to install a USB 3 hub on my desk .

    I don’t really miss the sound card that I had in the micro-ATX PC, and when I added some antennae to the motherboard’s built-in WiFi, it worked satisfactorily when I was traveling.

    • TwoEars
    • 7 years ago

    Unless you’re running a specialist board designed for baseclock overklocking of non-k model cpu’s it doesn’t. Well – maybe 5% but not much more. It’s all about the multipliers.

    • libradude
    • 7 years ago

    pretty much what I said, but got downvoted for it… wtf

    • Fonbu
    • 7 years ago

    I am surprised by all the daughter boards this has! Performs as well as it looks anyway.

    • LoneWolf15
    • 7 years ago

    [i<]GA-Z170N-Gaming 5 motherboard hides an M.2 slot on its back side, so the feature isn't unprecedented on Mini-ITX mobos.[/i<]. It's not unprecedented for ASUS either. My ASUS H97i-Plus ITX Haswell board has an M.2 slot on the underside as well.

    • LoneWolf15
    • 7 years ago

    People don’t buy Cadillac gamer boards for an HTPC.

    • slowriot
    • 7 years ago

    You’ve won today’s “Comment that left me shaking my head the most” award.

    • libradude
    • 7 years ago

    I doubt very many people wanting to put together a decent HTPC are going to want to drop 250 bones on this board. It’s designed for gamers/overclockers who will be putting a high(er) end video card in that PCI-E slot, not a tuner or a sound card. The built-in soundcard is actually pretty awesome for its size, and I believe they tout “best mITX sound” in the specs.

    • libradude
    • 7 years ago

    May I ask what mITX case you used? In my experience, that does make all the difference between a “wow, this went together great” build and a “man, I wish I’d never done this” situation.

    • EndlessWaves
    • 7 years ago

    A single HDMI 1.4 socket? That’s just a ridiculous. Even the cheapest H81 board these days offers better than that. Why on earth doesn’t this top of the range, money no object motherboard have triple DisplayPort outputs underneath that optical S/PDIF connector?

    Sure, many people won’t use it but I’m sure there are people building Mini-ITX systems and using the PCI-E slot for an enterprise SSD, TV tuner or high end sound card.

    • libradude
    • 7 years ago

    Great review! I just built a new system around this board in a SG08 case, and love it. A word about the M.2/U.2 tradeoff: I considered the mITX boards with m.2 on the back, but had read reports that the 950 Pro gumsticks I would be putting there have been throttling due to the heat they’re generating! I went with the Intel 750 2.5″ drive (system builders, note: it’s thicker than normal 2.5″ drives due to a beefy heatsink across the bottom) and have been very happy knowing my NVMe goodness is performing at its maximum, no throttling.

    So on a full ATX board where your M.2 port can be on the front and get ample cooling from your case fans, I think it’s a good fit – but on mITX where you pretty much have to put it on the back, I do think U.2 like what they did here is the better way to go.

    • Airmantharp
    • 7 years ago

    I’ll say this- if I were a single-GPU gamer, I’d be on ITX right now.

    • DragonDaddyBear
    • 7 years ago

    My problem with ITX is all of the crap I now have hanging off USB. I have replaced the space savings on my desk with clutter.

    • DancinJack
    • 7 years ago

    I have to agree. Having spent time with both (micro and mini-ITX), I strongly prefer micro-ATX if you have the room.

    • JustAnEngineer
    • 7 years ago

    I recently built a new gaming system in mini-ITX. That experience has reinforced my opinion that micro-ATX is the best form factor. Somethi ng like the Sugo SG10, Temjin TJ08-E or Silencio 352 provides a good home for what you need.

    • Firestarter
    • 7 years ago

    I’m clueless, how does the baseclock even impact performance these days?

    • chuckula
    • 7 years ago

    Hi Mark. Thanks for the review. Just two points.

    1. A question: For your own personal system would you consider this board in particular or another suitable mini-ITX board in general? I’m curious because as a long time user of full-sized ATX boards, I’m pondering what a future system build would look like, and it’s becoming less likely that it will be full ATX.

    2. A style comment: [quote<]Overall, it's impressive how much good stuff Asus has crammed into such a small motherboard. [/quote<] Let's fix that: [quote<]Overall, it's [u<][i<]unKrogothic[/i<][/u<] how much good stuff Asus has crammed into such a small motherboard.[/quote<]

Pin It on Pinterest

Share This

Share this post with your friends!