New Intel CPUs usually mean new motherboards, and MSI is diving into Coffee Lake with confidence. The company has at least a baker’s dozen of Z370 boards ready to go for prospective Coffee Lake builders, and the Z370 Gaming Pro Carbon AC is the last stop so far before one ascends to the Z370 Godlike Gaming in the lineup.
MSI is using the transition to Z370 as an opportunity to freshen its mainstream boards’ styling cues. The Pro Carbon still takes after automotive themes, but I daresay it’s grown up a bit since our experience with its Z270 cousin. No, we’re not looking at real carbon fiber on this board’s I/O shroud, but the subtle patterning on these accents is pleasant-looking enough.
I wish the company had lacquered over these accents for additional flair as it does on its higher-end Pro Carbon boards, but that’s an entirely personal preference. Even without that gloss, the MSI and Pro Carbon logos screened onto the board’s chipset heatsink and I/O shroud seem like they were applied at Maaco instead of in a pro’s paint shop. Maybe this is a sample defect, since other Pro Carbons I’ve seen in the wild have cleaner, more vivid white logos.
Compared to its predecessor, the Z370 Pro Carbon gets sportier-looking heatsinks covered with streamlined plastic accents. Pretty swanky. The downside of this new look is that the Pro Carbon’s heatsinks seem to give more to form than to function. Neither chunk of metal is particularly large, and they’re both partially covered by the plastic shroud that runs over them. That shrouding could reduce the effectiveness of these ‘sinks.
That partial coverage is especially concerning given the limited surface area afforded by the smooth and river-rock-like primary VRM heatsink to the left of the socket to begin with. This heatsink does have a few ridges and notches to break up its uniform surface, but again, those features seem mostly cosmetic instead of functional when you compare them to past generations of motherboard heatsink designs.
MSI also constructs the Pro Carbon’s heatsinks in a somewhat unusual fashion. The black secondary VRM heatsink is one piece of solid metal, but the silver primary heatsink uses a screw-in base plate to effect thermal transfer from the board’s primary voltage regulators to its metallic mass. Out of the box, this plate is coupled with the heatsink above by a modest smear of thermal interface material.
This construction method probably won’t make or break the performance of this heatsink, but it’s the first time we’ve seen such an arrangement in recent memory. (We conducted our thermal and overclocking testing before dissassembly, so our later comments will reflect the board’s out-of-box performance.)
I bring all this up because Intel’s highest-end Coffee Lake CPUs will demand more power from a motherboard’s VRMs than ever. These chips offer the highest number of potential cores and threads ever in a mainstream Intel socket. We’ve already seen evidence that an overclocked Core i7-8700K can get even a high-end power-delivery design with active cooling close to its thermal limits. We’ll see how the Pro Carbon AC handles a similar load in our overclocking tests.
Under those heatsinks, MSI relies on separate high- and low-side VRMs from ON Semiconductor plus a PWM controller from uPI. MSI chose ON Semi NTMFS4C024N MOSFETS for the board’s high-side switching duties and NTMFS4C029N MOSFETs with 46A ratings for its low side. Strangely enough, that PWM controller isn’t part of the components cooled by the board’s VRM heatsinks.
Although public documentation isn’t available for the uPI 9508Q PWM controller that MSI selected, the presence of three uPI MOSFET driver chips on the back of the board and another among the front-mounted VRM circuitry suggests the chip is capable of a 4+2-phase native topology.
Many boards include integrated Wi-Fi and Bluetooth using an M.2 slot these days, but MSI sticks to a pack-in PCIe x1 card to give the Pro Carbon its AC suffix. I laud the company’s choice of an Intel 8265N radio for wireless duties, but I do wish it had gone to the expense of wiring up an M.2 slot in the board’s I/O cluster instead of using a riser card. Burning a PCIe slot on what’s often a built-in feature might not sit well with the expansion-hungry.
In the memory department, MSI offers four DIMM slots capable of holding up to 64GB of RAM. MSI officially touts DDR4 multipliers ranging up to 4000 MT/s, but the Coffee Lake memory controller is capable of far higher speeds for extreme overclockers. Next, let’s take a look at the board’s expansion resouces and audio subsystem.
Expansion, I/O, and audio
As a full ATX motherboard, the Pro Carbon offers builders ample room for storage devices and expansion cards.
The first stop on our tour of the Pro Carbon’s expansion options is the primary M.2 slot and its integrated heatsink. This slot takes the place of the usual PCIe x1 slot that tends to be the first on many Z370 boards. In a nifty touch, MSI integrated the retaining screw for the SSD and the retaining screw for the heatsink into one fastener. Most other boards with integrated heatsinks use a traditional standoff for the M.2 drive itself and a separate screw for the heatsink, so I appreciate the convenience of this approach.
The board’s two CPU-powered PCIe x16 slots both get a full metal jacket to provide resilience against shearing forces when a builder moves or ships their PC. I’d always remove a hefty graphics card from a system before moving it or trusting it to a shipper, but MSI at least lets those not so inclined to try their luck.
The primary PCIe x16 slot gets 16 lanes of PCIe 3.0 from the CPU with one graphics card installed. Plugging another graphics card in for SLI or Crossfire splits those lanes into two x8 connections running to each metal-jacketed slot.
Chipset-powered PCIe slots occupy the remainder of the Pro Carbon’s board space. Each PCIe x1 slot gets a dedicated lane of PCIe 3.0 from the Z370 chipset. The last physical x16 slot on the board enjoys a dedicated x4 connection to the PCH, as well. Given the headache-inducing lane-sharing arrangements that pop up on some Z370 boards, the Pro Carbon’s straightforward layout is a breath of fresh air.
The Pro Carbon does perform some lane-sharing, but only in the storage department. In what I expect will be the most common arrangement, plugging an NVMe SSD into the primary M.2 slot on the Pro Carbon leaves all of the board’s SATA ports functional. Hallelujah.
SATA ports only start going dark on the Pro Carbon when one starts installing SATA devices in M.2 slots or when both M.2 slots are in use. Put a SATA drive in the first M.2 slot, and SATA port 1 goes dark. Put a second SATA M.2 device in the second M.2 slot, and SATA ports 1 and 5 both go offline. Put an NVMe SSD in the second M.2 slot, and SATA ports 5 and 6 go dark.
While builders will need to be careful about the protocol and position of their M.2 storage devices, the Z370 Pro Carbon will always offer at least four SATA ports to go with its M.2 slots. Storage-hungry builders should take note.
The Pro Carbon’s I/O cluster comes well-stocked with a mix of legacy and modern ports. Moving from left to right, the first stop is a PS/2 combo port for mice and keyboards. Two USB 2.0 ports from the Z370 chipset rest under this legacy connector.
A single DisplayPort 1.2 connector capable of running 4K displays at 60 Hz sits in the canyon between the old and the new on the Pro Carbon. To its right, we find a USB 3.1 Gen 2 Type-A port and a Gen 2 Type-C port, both powered by ASMedia’s latest-and-greatest ASM3142 controller. MSI backs up this high-speed chip with two PCIe 3.0 lanes from the Z370 chipset.
The next connector block in the Pro Carbon’s lineup houses two USB 3.0 ports from the Z370 chipset. These sit above an HDMI 1.4 connector capable of driving displays with resolutions up to 4096×2160 at 30 Hz. The next block over houses the RJ-45 connector for the board’s Intel I219-V Gigabit Ethernet controller and two more USB 3.0 ports from the Z370 chipset.
Like virtually every mainstream motherboard we see these days, MSI taps Realtek’s ALC1220 codec (under the Audio Boost 4 banner) for analog audio duties. MSI does include some Nichicon caps in the Pro Carbon’s audio chain, but headphone amp and DAC duties are all handled by the ALC1220’s built-in circuitry. The ALC1220 is a fine codec, but it’s presented in about as unadulterated a form as it can be on the Pro Carbon.
As a result, the Pro Carbon’s sound is serviceable, but not a standout among the other ALC1220-equipped boards that I’ve tried. The codec’s default voicing seems light on bass with a typically narrow stereo image. My preferred EQ curve (more bass, more highs, and less mids) livens up the Pro Carbon’s sound signature, as it does with other ALC1220 boards. That performance is just fine for basic audio output duties, but it’s not going to transport anybody to sonic nirvana in the same way that fancier onboard setups might.
MSI also offers Pro Carbon owners access to the Nahimic sonic sweetener software, for lack of a better term. Nahimic offers a wide range of potential audio massaging, but it takes forever to load on the Pro Carbon for some reason. Its enhancements also didn’t seem to do much that an EQ curve wouldn’t in its own right. I also wasn’t that impressed with the app’s simulated surround sound, whose output seemed more like a strong reverb than anything. Nahimic might be useful for its microphone noise suppression, but I’m not sure that feature is worth dealing with the app’s pokey performance and otherwise not-that-impressive audio enhancements. Give it a shot, but don’t expect miracles.
Firmware and Windows software
MSI’s Click BIOS 5 firmware still runs the show on the Pro Carbon, and it’s little changed from the company’s Z270 interface. In fact, Click BIOS 5 still owes a lot to the Click BIOS 4 interface from X99 and Z97 boards of years past.
That’s fine for the most part, since the interface is still straightforward and responsive. For a full-run-down of Click BIOS 5 and its features, check out our Z270 Pro Carbon review. Click BIOS 5 has come over to the Z370 version of this board without any major changes, so I’m not going to retread our past coverage here.
The Pro Carbon’s default handling of Turbo Boost behavior does deserve a note. Instead of goosing all-core Turbo ratios out of the box, as some motherboards do in a dubious effort to swing benchmark numbers, the Pro Carbon leaves well enough alone and lets builders decide whether and how they want to overclock their CPUs. That leads to predictable power-delivery and cooling demands, and MSI deserves praise for making this default choice. Bravo.
The Gaming App software for the Z370 Pro Carbon loses some responsibilities in the move from Z270 to Z370. The biggest loss is the clean, straightforward RGB LED controls that used to grace its function list for the Z270 Pro Carbon. More on that in a minute. In its Z370 iteration, the Gaming App provides one-click overclocking for the CPU and compatible MSI graphics cards. It’s also a portal to the Gaming Hotkey keyboard macro app, Mouse Master mouse macro and tuning utility, and the Dragon Eye and OSD applications.
Dragon Eye can overlay YouTube videos and Twitch streams on compatible games for folks who want to watch videos and play games at the same time, while the OSD app can show useful system information in a similar way. While these features are nice in principle, the limited list of compatible games means that folks who stray from supported applications will be out of luck if they need the features Dragon Eye and OSD provide. If your mouse or keyboard doesn’t come with a load of tweaking or macro options, the Gaming Hotkey and Mouse Master tools could come in handy.
Gaming App also offers built-in overclocking control for both the CPU and any compatible graphics cards. Although the mild clock-speed differences among some graphics cards’ various clock-speed profiles are already well-understood quantities, the effects of MSI’s performance profiles on the CPU were less clear to me at first glance.
Indeed, applying “Gaming Mode” to the CPU didn’t make any immediately obvious changes, but some digging revealed that the Gaming App silently switches the PC’s power plan to “High Performance” in this mode. You can’t change your power plan back to “Balanced” in this mode because the Gaming App will step in and reset it to “High Performance” for as long as you have “Gaming Mode” selected. Enthusiasts might set their power plans to “High Performance” often enough on their own time that MSI’s decision to apply this change in the background might not raise too many eyebrows.
My contention with this behavior is that it’s done silently. In the grand scheme of things, the “High Performance” power plan only results in a few more watts consumed at idle, going by my power meter, but builders may still wonder why their machine never goes to sleep on its own, for just one example of how a change in power plans can affect systems. Just as we have with “multi-core enhancement” stealth overclocks in the past, I’d encourage MSI to be more forthcoming about changes to a user’s system settings if it’s making them.
Similarly, Gaming App’s “OC Mode” for the CPU doesn’t offer any suggestion as to its effects on a system before it’s selected, although enabling that mode does result in a system restart and a cautionary message not to perform firmware updates or modify CPU-related firmrware settings with that performance profile enabled. (Curiously enough, the system power plan for “OC Mode” remains “Balanced.” Life is strange sometimes.)
To figure out what OC Mode’s effects on my Core i7-8700K were, I fired up the CPU-Z monitoring tool and MSI’s own Command Center app. As it happens, OC Mode applies a 100-MHz boost across the board to Intel’s stock Turbo tables, meaning the chip will run as high as 4.8 GHz under lightly-threaded workloads and at 4.4 GHz for all-core Turbo speeds. OC Mode also applies a fixed 1.2 V to the chip’s Vcore parameter.
Although a minor overclock like the one Gaming App can apply is fine in isolation, the fact that it doesn’t cleanly reset the system to stock settings when a user disables the profile is less desirable. Even after I reset the Gaming App to Silent Mode for the CPU, MSI’s own Command Center app confirmed that the CPU’s Turbo tables retained the 100-MHz bump that OC Mode applied. Only a full firmware reset restored the CPU to its default Turbo settings. Gaming App should cleanly restore the system to its defaults if a user chooses to disable its pre-baked profiles after applying them.
The second major piece of Windows software that MSI provides, Command Center, is also little changed from its appearances with past motherboards. In its most basic view, the app provides real-time monitoring and control over CPU clock ratios for manual overclocking, and it also shows CPU temperatures and fan speeds. Among its more advanced options, Command Center can control a variety of CPU voltages, DRAM voltage and timing (albeit not frequency), integrated graphics processor frequency, and the same Game Boost 100-MHz Turbo table bump that the Gaming App provides.
Although Command Center provides some useful knobs and levers for basic tweaking in Windows, I’m not a fan of the manual save-and-load-a-profile dance that one has to perform in order to keep or apply those custom settings. Storing those settings should be a one-click operation at most, and the software should be able to recall them automatically upon reboot. This isn’t especially inconvenient for manual overclocking, since one can do it in the firmware. This manual memory-jogging really becomes annoying when it comes time to control fans attached to the Z370 Pro Carbon.
The Z370 Pro Carbon gives builders five four-pin fan headers to play with. Each of these can automatically sense and control three- or four-pin fans, a welcome feature from a high-end motherboard.
Compared to recent efforts from Gigabyte and Asus, though, MSI’s fan controls are feeling a bit dated. The Hardware Monitor fan-control utility in of Click BIOS 5 is identical to that of the Z270 Pro Carbon’s, so the Z370 iteration of this formula offers no choices for temperature sources. As a result, builders are at the mercy of whatever the firmware believes is the best reference temperature for each header.
Adding insult to injury, the Z370 Pro Carbon only has two temperature sources across the entire board: one motherboard temperature sensor and the CPU core temperature. The flexibility and diverse range of sensors from Gigabyte’s recent Smart Fan 5 firmware utility makes this lack of tunability especially stark.
Hardware Monitor also doesn’t offer a firmware-based fan calibration routine. To be fair, only Asus motherboards have this feature among the modern mobos I’ve used, but its absence means that builders will need to manually guess and check the lower bound of their fans’ speed ranges.
In theory, MSI’s Command Center Windows software should provide that auto-sensing convenience. The utility’s fan-calibration tools have a major problem, though: they’ll run the standard sweep of fan speeds just like every other motherboard auto-calibration routine on the planet, but Command Center doesn’t seem to do anything meaningful with that data.
Even after running the fan-calibration routine, it’s possible to set fan curves in the Command Center interface that will run below the minimum fan speed that the software presumably worked to find in the calibration routine. Without those lower limits, it’s just as necessary to guess-and-check the range of fan speeds available from each spinner as it is in the firmware.
Worse, Command Center doesn’t even remember a user’s custom fan-speed curves for re-application on every reboot. Instead, Command Center makes it necessary to manually save fan curves for later use and apply them manually at each start-up. Command Center doesn’t even remember one’s preferred fan-control method; it just defaults to a fixed 50% speed on every reboot. This laborious hands-on approach simply isn’t necessary with fan-control systems from other motherboard makers, and it’s a serious pain for anybody who shuts down their machine regularly.
Since Command Center’s fan-control interface offers essentially no functional advantages over the Hardware Monitor interface in the Pro Carbon’s firmware, I would set up my preferred curves in the firmware and leave it at that.
Whatever we might think of them, arrays of RGB LEDs have become central features of most every modern motherboard, peripheral, and component. We’re long past the point where protesting the presence of these blinkenlights is useful. They are well and truly ubiquitous, and they’re not going away. If you can’t stomach them, the answer is simple: turn them off.
As reviewers, our main concern now is making sure motherboard makers are making RGB LEDs easy to configure and manage across a system. Given the ranges of color, animation, and synchronization available from modern RGB LEDs, the potential complexity of lighting management is daunting, and it’s a major challenge for motherboard makers to rein in that complexity in software.
Like many of today’s motherboards, the Z370 Pro Carbon offers a wealth of onboard RGB LEDs and headers for a variety of add-on light strips. The board has two headers for standard 5050 LED strips, a header for individually-addressable RGB LEDs, and a dedicated connector for use with Corsair RGB LED fans.
Even if you’re not installing a truckload of RGB LED peripherals and add-ons in your system, the Z370 Gaming Pro Carbon offers a decent array of lighting options of its own. The I/O shroud, chipset heatsink, a practically-invisible “motherboard function LED,” and the lighting tracks on the board’s lower-left and upper-right edges can all be synced up or controlled separately.
In operation, the Z370 Pro Carbon’s RGB LEDs are subtle. The chipset, I/O shield, and audio-track LEDs are all diffused or only indirectly visible, and the row of LEDs next to the DIMM slots isn’t visible from the front face of the motherboard of the board at all. If you prefer to create a mood rather than sear your retinas, the Pro Carbon’s approach should be pleasing to your eye.
All those headers and LEDs are nothing without software to control them. Of late, MSI has broken RGB LED control for its products into a new utility called Mystic Light. Compared to the clean, simple, and straightforward RGB LED controls in the company’s Gaming App for Z270 boards, Mystic Light feels like a step backwards.
From its first launch, the app doesn’t make a great impression. The app window can’t be resized, and it takes up the majority of the screen. The window is also semi-transparent, so its legibility will be affected by content and windows behind it. The mere process of using Mystic Light isn’t entirely straightforward, either. The main interface of the app presents a view of every Mystic Light-compatible component or peripheral associated with a system. If you only want to set every RGB LED-bedecked piece of hardware in your system to the same lighting and animation patterns, the main screen of Mystic Light wlil get you there. Secret trick: double-clicking on a color swatch in MSI’s main interface will bring up a color picker and let you save a custom color of your choice (they’re all red to begin with).
Life gets a little trickier if you’d rather configure each component individually. Mystic Light simply does not make it obvious how to control individual pieces of hardware. After some trial-and-error, I learned that it’s necessary to click twice on the icon for a given piece of hardware until it becomes highlighted in gray. A further single click on a device will highlight its icon in red, which adds it back to the sync pool after you click anywhere else in the interface.
If you like studying the behavior of state machines, you will enjoy using Mystic Light.
Once a given piece of Mystic Light hardware is selected in gray, one can apply individual lighting effects to it using the main interface and further select the color associated with those effects, where applicable. To play with more advanced settings that aren’t common to every piece of hardware in a system (more on that in a moment), it’s necessary to double-click a piece of hardware, ensure that its icon remains gray, and then find it in the list of Mystic Light “Device Setting” choices in the lower-left-hand corner of the interface.
In this per-device view, Mystic Light will offer up more detailed controls for a given component’s lighting modes, including a list of supported animations, a color picker, and a swanky preview of how those selections will look when they’re applied to the piece of hardware in question. Oddly enough, though, not every Mystic Light-compatible device will work the same way. For one example, the GeForce GTX 1070 Gaming Z graphics card I used as a companion for the Pro Carbon doesn’t support the rainbow cycling mode that typifies so much RGB LED-bedecked hardware these days, while the motherboard itself does. As a result, one loses the option to sync that animation type across all Mystic Light products in a system, and it’ll become necessary to individually assign it to the devices a builder would like to look that way.
Although RGB LED software in general is not the greatest exponent of polish and stability, Mystic Light still falls short. Late in my testing, the software straight-up lost the ability to control the motherboard’s onboard LEDs. At that point, the software couldn’t convince the Pro Carbon to do anything but the rainbow lighting effect I had set at some point beforehand. Even across multiple CMOS resets, different operating system installations, and even after letting the motherboard sit without power or a CMOS battery for an extended period, the Pro Carbon wouldn’t let me do anything but taste the rainbow.
By some miracle combination of settings invocations and profile choices, though, I eventually got Mystic Light and the Pro Carbon communicating again. I honestly cannot recount the exact set of steps I took to get Mystic Light working again beyond poking and praying, and the loss of control I experienced made me gun-shy about further LED tweaking. A less-patient user might reasonably conclude that the software or the motherboard itself was irreversibly broken.
All told, Mystic Light ranks as the least-refined implementation of an RGB LED control utility that I’ve used from the big three motherboard manufacturers so far. Although MSI’s developers have the right set of features in mind with the app’s extensive sync capabilities, actually using Mystic Light proved a frustrating experience, and its eventual ignorance of my commands was the straw that broke the camel’s back for my patience with it.
Every CPU has different overclocking potential as a consequence of the vagaries of semiconductor production. The job of the motherboard, then, is to make it as easy as possible to extract the maximum performance potential of each chip in a straightforward manner without causing undue risk to the hardware at hand. Most modern motherboards also offer a suite of automatic overclocking tools to let even novices try their hands at pushing frequencies to the moon, and the effectiveness of those features could tip newbies’ favor to one board over another.
My first stop on the road of voided warranties with the Pro Carbon was in the memory department. I rarely have to think twice about turning on XMP with today’s motherboards, but the Z370 Pro Carbon proved an exception with its initial firmware. Even with voltage tweaks, I couldn’t ever get the board to boot using only XMP settings with the otherwise-dependable G.Skill DDR4-3600 RAM I use in my other Intel test rigs. Manually dialing RAM speeds back to DDR4-3466 let the board run as expected during my initial testing.
Late in my tests, I tried running the XMP profile with 1.39V for the DRAM, and that was apparently enough juice to get the system stable at 3600 MT/s speeds. Still, I’ve rarely had to dial in that much DRAM voltage in order to get a system stable, especially with $200 motherboards of late. Even later in my testing, MSI issued a firmware update for the board that let the system take advantage of our memory kit’s XMP parameters without the big shot of extra voltage I initially needed to get it stable. I’m cheered by the fact that the initial difficulties I observed weren’t baked into the Pro Carbon’s hardware, at least.
Next, it was time to see what the board could do with our Core i7-8700K CPU. We generally like to begin our overclocking attempts using a company’s automatic methods, but MSI doesn’t provide an iterative automatic tuning utility like Gigabyte and Asus do. Instead, its Command Center software and the Gaming App have a one-click option that will simply apply a 100-MHz boost to Intel’s stock Turbo tables for the Core i7-8700K, along with a 1.2 V fixed Vcore. That’s barely an overclock, and our chip was more than capable of handling it. With that one-click boost exhausted, I proceeded to manual tuning.
In a way, Coffee Lake CPUs make overclocking boring, because without a delid and repaste, thermal headroom seems to be the primary obstacle to extracting the most from a given CPU. We already know that our particular Core i7-8700K can handle 5 GHz in lightly-threaded workloads with a -2 AVX offset before further voltage increases cause thermal throttling, so the question is really how easily one can get there on a given Z370 motherboard.
Strangely enough, I discovered that MSI doesn’t expose any kind of adaptive voltage control or even an offset voltage mode on the Z370 Pro Carbon in the firmware’s default configuration: it’s fixed voltage or nothing. That old-school approach means the CPU will run at our chosen Vcore 100% of the time, even at light workloads and at idle. A fixed 1.35 V Vcore results in 15 W to 20 W more idle power draw or so compared to stock speeds and a dynamic Vcore, by my measurements. Although that’s not a lot, it will add up over time if you leave your system on 24/7.
Although I didn’t use it in my testing, MSI does offer the offset and adaptive modes I prefer, so long as you enable the “Expert” OC Explore mode in the firmware first.
Although the Pro Carbon had no trouble taking our particular Core i7-8700K to its thermal limits, the motherboard seemed to run into some thermal trouble of its own under our Prime95 test load. The Pro Carbon doesn’t have a VRM temperature monitoring diode to track, and our FLIR One camera has some annoying parallax that makes it hard to determine exactly how hot a given component is getting.
Still, after just a few minutes running Prime95, I noticed the fans on our test rig’s liquid cooler spinning down and ramping up again under that Prime95 load. The CPU wasn’t throttling due to thermal limits, so the issue appeared to come from some component in the board’s power-delivery subsystem reaching at least 100° C, according to our FLIR camera.
The HWiNFO64 utility also revealed that the “IA: VR Thermal Alert” flag was being set when these throttling dips happened, so the culprit is almost certainly VRM temperatures. The same firmware that solved my XMP annoyances contained a note about fixing throttling behavior under Prime95 stress testing, but if anything, that firmware update seemed more sensitive to VRM temperatures, not less.
Admittedly, I run my motherboard tests on an open bench—not an environment typical of where the Pro Carbon will usually operate. Still, even after simulating case airflow by positioning our 280-mm radiator right next to the motherboard and resting a 140-mm fan directly on the I/O shield, the Pro Carbon continued to throttle while we attempted to max out our Core i7-8700K with Prime95 at 1.35 V. Lowering the voltage to 1.32 V and running with a -2 AVX offset only extended the period between throttling dips; it didn’t take care of the behavior entirely.
Dropping a 140-mm fan directly on the socket is not going to be typical of how many builders will configure their systems, but it’s how I had to run my test bench in order to keep the Pro Carbon running at full speed. Given our simulated case-airflow testing, even three 140-mm fans providing indirect airflow aren’t enough to keep this board’s VRMs happy at the edges of their temperature range. A directed fan of some kind would seem to be good insurance for keeping the Pro Carbon running all-out under extreme stress testing.
As I noted in the introduction of this article, the problem may be that the Pro Carbon’s VRM cooling seems to give away too much to form over function. The Pro Carbon’s VRM heatsinks are largely smooth chunks of metal topped off with plastic decorative shrouds that reduce the already-limited surface area given over to heat dissipation. As we’ve surmised in the past, such designs weren’t an issue with quad-core CPUs, but the added power draw of six-core chips seems to be enough to push VRM temperatures over the edge with a stress test.
To be fair, Prime95 Small FFTs is a synthetic workload that draws much more power than even some of our most demanding CPU benchmarks with AVX instructions. For a sanity check, I fired up the challenging “classroom” benchmark for Blender with our overclocked Core i7-8700K and let it run its course. During that period, even with the CPU set to a maximum of 1.35 V (as some more extreme overclocks might need for all-core AVX stability), the system drew a whopping 85W less than with Prime95 Small FFTs under the same conditions.
Handbrake, another real-world application that uses AVX, tends to have much greater variance in system power draw, but even its peak power draw runs about 60 W short of that of Prime95 Small FFTs. Even looping the standard Handbrake encode that we use for CPU reviews, I didn’t observe any throttling of the type that Prime95 Small FFTs caused.
Given that performance, the Pro Carbon’s VRM heatsinks are probably fine for real-world overclocking. Just don’t expect to perform a 24-hour stress test of Prime95 without some kind of active cooling on the socket. Even with the results of our follow-up testing in mind, it would still be nice to see future VRM heatsink designs prioritize function over form from all major motherboard manufacturers, not just MSI.
MSI’s Z370 Gaming Pro Carbon AC dives into Coffee Lake with fresh looks and a tasteful approach to RGB LED lighting. Given our past experience with the company’s Z270 boards, I was expecting a solid, no-nonsense enthusiast motherboard for its $200 price tag, and in many ways, the Z370 Pro Carbon is just that.
We got a hint that VRM cooling could be a challenge for Z370 motherboards from Gigabyte’s Z370 Aorus Gaming 7, and indeed, the Z370 Gaming Pro Carbon’s VRM heatsinks didn’t seem up to the task of keeping that circuitry cool under our worst-case Prime95 Small FFTs testing. I observed VRM-temperature-related thermal throttling under that workload, even with simulated case airflow over the socket. In our real-world tests, the Pro Carbon’s VRM cooling proved adequate, though, so this behavior may only be of concern to extreme overclockers and those with low-airflow cases.
For the unwashed masses, there are other points of concern for the Pro Carbon. MSI’s software suite for the Z370 generation is less refined than that of other recent motherboards we’ve used. The Mystic Light RGB LED utility is a chore to use. MSI also hasn’t overhauled its firmware or basic fan-control approach in some time, and the Pro Carbon’s options for fan management feel unpolished and limited next to recent efforts from the competition. The Gaming App’s pre-baked performance profiles aren’t 100% transparent about what they’re actually doing behind the scenes, and resetting those profiles to their defaults doesn’t necessarily remove the performance-boosting settings they apply.
Even if MSI’s software could use a freshening-up, the Pro Carbon itself has plenty of thoughtful touches. I most appreciate MSI’s sensible allocation of PCIe lanes from the Z370 chipset. Putting an NVMe SSD in the board’s primary M.2 slot doesn’t disable any SATA ports for the storage-hungry, a common-sense decision that’s surprisingly unusual in today’s motherboards. I appreciate MSI’s elegant M.2 heatsink design, as well.
The Pro Carbon’s array of fan headers offer automatic sensing of three- and four-pin fans, another nice convenience that’s often missing from lesser hardware. Extras like a bundled Wi-Fi card, a thermally-shielded M.2 slot, and a padded I/O shield help distinguish the Pro Carbon from run-of-the-mill mobos.
MSI makes some good default firmware choices on the Z370 Pro Carbon, too. The company has joined Gigabyte in letting Intel’s stock Turbo Boost multipliers run the show instead of goosing the chip to its all-core Turbo speed out of the box, so builders who want predictable stock-clocked behavior from their motherboards can rest easy with this one.
All told, the Z370 Gaming Pro Carbon AC has solid bones, but it lacks the overall polish that we’ve come to expect from the best $200 motherboards. With better fan controls, more detailed temperature monitoring, and more polished software, the Z370 Gaming Pro Carbon would be an easy choice for enthusiast Coffee Lake builds. As it stands, though, the Pro Carbon offers solid hardware paired with software that needs lots of patience to love.