AMD’s 785G integrated graphics chipset

As a PC enthusiast, my attention naturally gravitates toward the bleeding edge. I can’t help but want to see what’s new, what’s fast, and what’s coming up next. These days, though, it’s hard to justify lusting after a high-end system. The vast majority of applications are still single-threaded, and even those who multitask can generally get by with an affordable dual-core CPU. Additionally, the prevalence of games designed primarily for the dated hardware underpinning the current generation of consoles has ensured that you don’t need to spend much more than a $150 to enjoy the latest games with all their eye candy enabled on monitors up to 24 inches.

Heck, if you don’t play games, you don’t even need to buy a graphics card. Today’s integrated graphics chipsets are certainly up to the task of handling standard desktop applications, and they’re endowed with high-definition video decoding capabilities. They even sport a couple of digital display outputs, should you wish to run a multi-monitor setup without futzing with analog conversions.

Even the motherboards based on modern integrated graphics chipsets are pretty good. Years ago, it seemed motherboards with integrated graphics were designed exclusively for system integrators and major PC brands looking to crank out budget systems with little flair and only the bare minimum of function. While adequate for mainstream folks, these boards were a little low-rent for enthusiasts. Fast-forward to the present day, however, and you’ll find that the landscape has changed dramatically. You can now get full-featured integrated graphics boards loaded with BIOS tweaking and overclocking options, high-quality electrical components, plentiful I/O ports, and even dual PCI Express x16 slots.

Since enthusiasts have traditionally been gamers, few of us have stripped the discrete graphics cards from our primary desktops. We have, however, expanded the number of PCs in our homes, adding media-centric home theater PCs, closet file servers, and even little systems tucked away in our kitchens. These auxiliary machines tend not to play games, making them perfect candidates for integrated graphics.

Such as those provided by AMD’s new 785G chipset, perhaps.

Descended from the 780G, our favorite integrated graphics chipset for the better part of a year and a half, the 785G’s pedigree is impressive. That’s important, because the 785G is very much like its predecessor.

Despite this strong family resemblance, the 785G is more than a marketing-driven model number uptick to denote support for the latest Socket AM3 processors. The chipset’s north bridge component is all-new silicon, albeit built on the same 55nm node as its forebear, with roughly the same number of transistors. Some 205 million transistors made up the 780G’s north bridge silicon, and AMD says that number hasn’t gone up by much for the 785G.

So what does a modest increase in transistors get you? A new RV620 graphics core otherwise known as the Radeon HD 4200. As its name implies, this integrated GPU has all the enhancements one might expect from the Radeon HD 4000 series, including support for DirectX 10.1. However, the number of stream processors remains the same. Like the Radeon HD 3200 found inside the 780G, the 4200 GPU has 40 stream processors ticking at 500MHz. They don’t run at that speed all of the time, though; the 785G’s PowerPlay energy saving scheme constantly adjusts clock speeds based on GPU utilization, bringing the core down to just 60MHz when idling. Indeed, all the internal clocks inside the 785G scale dynamically to save power, although chipset voltages remain constant.

Rather than having the 785G’s integrated Radeon cannibalize system memory bandwidth and capacity, motherboard makers have the option of pairing it with dedicated “sideport” memory of its own. Sideport memory was an option on the 780G, too, but few mobo makers took advantage of it. AMD says that has changed with the 785G, with more boards expected to sport dedicated video RAM.

Much like its 3D core, the Radeon HD 4200’s Universal Video Decoder (UVD) has also been tweaked. This second-gen UVD block retains the original’s ability to handle the lion’s share of processing associated with Blu-ray playback across all three common formats. Now it can apply that decode acceleration to multiple streams, which is perfect for the picture-in-picture commentary tracks included with some new movies. Also new in the 785G’s UVD is the ability to perform detail enhancements on the fly.

In another nod to the home theater PC crowd, AMD has upgraded the 780G’s HDMI 1.2 support to version 1.3 for the 785G. However, the new chipset retains its predecessor’s inability to pass uncompressed multi-channel LPCM audio over HDMI—a capability competing integrated graphics chipsets possess. The 785G can’t pass TrueHD or DTS-HD audio over its HDMI output, either.

Although its embedded Radeon is really the star of the show here, the 785G is more than just a GPU. The chipset’s north bridge component also houses a 2GHz HyperTransport link compatible with the latest Socket AM3 processors. It also has 22 second-generation PCI Express lanes split between a single x16 link for graphics and six x1 links for expansion slots and onboard peripherals. The chipset can’t split its x16 link in order to feed a pair of x8 connections, though. That will force motherboard makers to get creative if they want to support CrossFire configs that extend beyond pairing an ultra-low-end Radeon with the integrated GPU. The Radeon HD 4200 can’t participate in CrossFire configs with discrete graphics cards that posses substantially more horsepower.

Like the rest of AMD’s core-logic lineup, the 785G uses PCI Express to link its north and south bridge components. A pipeline offering 2GB/s of bi-directional bandwidth sits between the 785G and its SB710 sidekick.

The SB710 is essentially an SB750 without support for RAID 5 arrays. The chip still has six 300MB/s Serial ATA ports, but they’re limited to RAID 0, 1, and 0+1. AMD also throws in a single ATA channel so mobo makers don’t have to use auxiliary peripheral chips just to provide an IDE port.

A dozen USB ports and a high-definition audio interface round out the SB710. Support for next-gen USB and SATA standards would have been nice here, but keep in mind we’re talking about a budget chipset targeted at sub-$100 motherboards.

Asus’ M4A785TD-V EVO motherboard
Unexpectedly ATX

Manufacturer Asus
Model M4A785TD-V EVO
Price (Street) $100
Availability Now

The first 785G-based motherboard to hit the Benchmarking Sweatshop was Asus’ M4A785TD-V EVO. And it doesn’t look anything like an integrated graphics motherboard. For starters, the EVO is a full-size ATX model with a larger footprint than the Micro ATX designs generally associated with integrated graphics. Asus has put the extra board real estate to good use, dropping in a couple of physical PCI Express x16 slots to support traditional two-way CrossFire configs. The top (blue) slot gets a full 16 lanes of bandwidth, while the bottom (white) slot has to make do with just four. Keep in mind that these are PCIe 2.0 lanes, though; a gen-two x4 link offers just as much bandwidth as a gen-one x8 link.

With careful color-coordination, the EVO is certainly more stylish than most low-end mobos. The blue slots and ports nicely play off the brown PCB, although I can’t help but wish Asus had gone with a different base color. You can call the shade auburn, mocha, or chocolate, but it still looks like poo brown to me. Or worse, Zune brown.

Under the EVO’s brown veneer lurks a circuit board layered with two ounces of copper to reduce impedance and aid heat dissipation. Fancy solid-state capacitors are used throughout, as well. That’s a given on mid-range and high-end motherboards, but it’s considerably less common among the EVO’s sub-$100 rivals. The EVO’s 8+2-phase power solution is also considerably more robust than we’re used to seeing on budget fare. Curiously, though, the board only has a four-pin auxiliary 12V power connector.

The EVO capitalizes on the 785G’s Socket AM3 aspirations with four DDR3 memory slots and the necessary BIOS multipliers to run 1600MHz DIMMs without overclocking the system’s CPU or base clocks. As with most AMD-based motherboards, the DIMM slots are close to the socket, which can create clearance problems for those looking to pair tallish memory modules with aftermarket CPU coolers that fan out from the socket.

Otherwise, the EVO is devoid of niggling layout or clearance issues. Lengthy PCI Express graphics cards won’t obscure access to the IDE or Serial ATA ports, and you can even pop a longer expansion card into the top x1 slot without interfering with the north bridge cooler.

Although it might have been nice to get a DisplayPort output, I can find little fault with the EVO’s port complement. There’s a little something for everyone here, including a PS/2 keyboard port that, despite its purple hue, also works with mice. However, I’m not crazy about the fact that the audio outputs are powered by a VIA audio codec that doesn’t support real-time DTS or Dolby Digital Live encoding. Bummer.

As one might expect from an Asus motherboard, the EVO’s BIOS is loaded with tweaking and overclocking options. There’s plenty of range for the sort of modest overclocking one might attempt with an integrated graphics board, and Asus makes setup easy by allowing users to enter most clock speeds and voltages manually rather than forcing them to scroll through expansive lists of available options.

Somewhat disappointingly, the BIOS doesn’t include independent control over the processor’s north bridge multiplier. Asus makes up for this omission by offering more robust fan speed controls than we’re used to seeing. The automatic fan speed control options on Asus motherboards are generally limited to three pre-defined profiles. With the EVO, however, one has control over not only the starting CPU fan voltage, but also the temperature triggers that dictate when the fan spins up and when it’s cranked to full speed.

Gigabyte’s GA-MA785G-UD3H motherboard
Clinging to DDR2

Manufacturer Gigabyte
Model GA-MA785G-UD3H
Price (Street) $90
Availability Now

Like the Asus EVO, Gigabyte’s MA785G-UD3H is a full-size ATX board with dual PCIe x16 slots for CrossFire. The UD3H’s slots even share the same x16/x4 lane configuration as the Asus board. And that’s not all. Like the EVO, the UD3H has two ounces of copper spread between its circuit board layers. Solid-state capacitors carrying the same 50,000-hour rating as those on the Asus board can be found throughout, as well.

The UD3H is a little cheaper, though. At Newegg, it’s currently selling for $10 less than the EVO.

A lower price tag suits the UD3H in part because it’s equipped with DDR2 rather than DDR3 memory slots. This makes the board compatible with a range of older Socket AM2 and AM2+ processors that lack DDR3 memory controllers. DDR2 is slower than DDR3, of course, and the BIOS only supports memory DIMMs up to 1066MHz before you have to start cranking on the system’s base clock. System memory speed is particularly important here because available memory bandwidth must be shared with the board’s integrated Radeon. Unlike the EVO, which packs 128MB of DDR3-1333 sideport memory, the UD3H’s graphics component doesn’t have dedicated memory of its own.

I suppose since I called out the EVO for being brown, I should chime in on the UD3H’s rather garish color scheme. The turquoisey-blue board is a given here, but the Technicolor array of nearly neon expansion ports and slots looks horribly tacky next to the more tasteful palettes used on some of Gigabyte’s recent mid-range and high-end mobos. A little restraint goes a long way.

Those who prefer to treat their motherboards’ integrated graphics components as backups rather than primary GPU options will be pleased to know that it’s easy to pop one or two discrete graphics cards into the UD3H. However, if you’re going to run two, be aware that longer double-wide cards installed into the bottom (orange) x16 slot can compromise access to two of the board’s SATA ports. Double-wide CrossFire configurations probably won’t be common in systems built around a $90 integrated graphics board, but it nonetheless irks me to see an avoidable clearance issue rear its ugly head, especially since the rest of the board is so well laid out.

At least the UD3H has plenty of expansion slots on offer, including one more than the EVO. Gigabyte also biases the board’s expansion capacity toward PCI Express rather than PCI slots—a smart move given the growing number of PCIe peripherals on the market.

Unfortunately, Gigabyte hasn’t seen fit to grace the UD3H with eSATA connectivity. The UD3H does have a hybrid PS/2 port that can handle either mice or keyboards, though. That isn’t much consolation, but then eSATA probably won’t hit its stride until the next-gen standard arrives with built-in power.

Gigabyte has done better on the audio front by endowing the UD3H with Realtek’s flagship ALC889A codec chip. We don’t normally get excited about crab-flavored codecs, but this one supports real-time Dolby Digital Live encoding, allowing users to pass multi-channel game audio unfettered by analog conversions over a single digital cable to a compatible receiver or speakers.

Dual BIOS chips are something of a tradition with Gigabyte, and the UD3H can easily fall back onto its reserve chip should corruption foul the primary one. The BIOS itself is well organized, and like the EVO, there are plenty of overclocking and tuning options to explore. Gigabyte’s BIOS isn’t quite as easy to use as Asus’, though. One cannot input voltages and clock speeds arbitrarily, so most options must be selected from lists or flipped through by hammering the + and – keys. Only the base clock speed can be keyed in manually.

Since BIOS-level fan speed controls are a pet peeve of mine, I should also point out that the UD3H offers little in the way of fan speed tuning. You can enable automatic fan speed control and tell the BIOS whether you’re using a three- or four-pin fan, but that’s it. Unlike with the EVO, there’s no way to define fan voltages or temperature triggers.

The devil’s in the details

This wouldn’t be TR motherboard coverage without a painstakingly detailed assessment of each board’s BIOS options and specifications. These details don’t exactly lend themselves to eloquent prose, but you should be able to find what you need in the tables below.

Asus M4A785TD-V EVO Gigabyte MA-785G-UD3H
Clock speeds Base: 200-550MHz in 1MHz
increments
DRAM: 400,533,667,800MHz

PCIe:
100-150MHz in 1MHz increments
HT
: 200-2000MHz in
200MHz increments
GPU: 150-1500MHz in 1MHz increments
Base: 200-500MHz in 1MHz
increments

PCIe:
100-200MHz in 1MHz increments
HT: 200-2600MHz in
200MHz increments

GPU: 200-2000MHz in
1MHz increments

Multipliers CPU: 5X-15X in 0.5X increments CPU: 5X-15X in 0.5X increments
CPU NB
5X-10X in 1X increments
DRAM: 2X, 2.66X, 3.33X, 4X, 5.33X
Voltages CPU: 1.025-1.7V in 0.00625V increments

CPU NB: 0.875-1.55V in 0.00625V increments

CPU VDDA: 2.5-2.8V in 0.1V increments

DRAM: 1.5-2.231V in
0.015V increments

HT: 1.2-1.35V in
0.015V increments
Chipset: 1.1-1.61V in
0.015V increments

CPU: -0.6-+0.6V in 0.025V increments

CPU NB: -0.6-+0.6V in 0.025V increments
DRAM
:
+0.1-0.5V in
0.1V increments

NB:
+0.1-0.3V in
0.1V increments

SB
: +0.1-0.3V in
0.1V increments

Monitoring Voltage, fan status, and
temperature
Voltage, fan status, and
temperature
Fan speed control CPU, system CPU, system

The multiplier options listed above are what’s presented with an Athlon II X2 250 processor. Expect support for higher multipliers if you’re using a Black Edition CPU with an unlocked upper multiplier.

Asus M4A785TD-V EVO Gigabyte MA-785G-UD3H
CPU support Socket AM3-based
Athlon, Phenom, Sempron 100 series processors
Socket AM3/AM2+/AM2-based
Athlon, Phenom, Sempron processors
North bridge AMD 785G AMD 785G
South bridge AMD SB710 AMD SB710
Interconnect PCI Express 2.0 (2GB/s) PCI Express 2.0 (2GB/s)
Expansion slots 2 PCI Express x16
1
PCI Express x1

3 32-bit/33MHz PCI

2 PCI Express x16
3
PCI Express x1

2 32-bit/33MHz PCI

Memory 4
240-pin DIMM sockets

Maximum of 16GB of DDR3-800/1066/1333/1600 SDRAM

4
240-pin DIMM sockets

Maximum of 16GB of DDR2-800/1066/1333 SDRAM

Storage I/O Floppy disk

1 channel ATA/133

5 channels 300MB/s Serial ATA with RAID 0, 1, 0+1

Floppy disk

1 channel ATA/133

6 channels 300MB/s Serial ATA with RAID 0, 1, 0+1

Audio 8-channel HD audio via VIA
VT1708S codec
8-channel HD audio via Realtek
ALC889A codec
Ports 1 PS/2 keyboard/mouse

1 HDMI

1 VGA
1 DVI
1 eSATA
6
USB
2.0 with headers for 6 more

1 RJ45 10/100/1000
via Realtek RTL8112L
1 1394a Firewire via
VIA VT6308P with header for 1 more


1 analog front out

1 analog bass/center out
1 analog
rear out
1 analog surround out

1 analog line in

1 analog mic in

1 digital S/PDIF out (TOS-Link)

1 PS/2 keyboard/mouse
1 HDMI

1 VGA
1 DVI
6
USB
2.0 with headers for 6 more

1 RJ45 10/100/1000 via Realtek RTL8111C
1 1394a Firewire via TI TSB43AB23 with headers for
2 more

1 analog front out
1 analog bass/center out
1 analog
rear out
1 analog surround out

1 analog line in

1 analog mic in

1 digital S/PDIF out (TOS-Link)

Our testing methods

The two 785G boards we’re looking at today are already selling for an affordable $90-100, but that’s apparently a little richer than AMD expects for the platform. Typical 785G boards will be Micro ATX models that AMD says should sell for closer to $80, or possibly even less.

With an eye towards the 785G’s budget target, we’ll be testing the Asus and Gigabyte boards against an LGA775 platform powered by Intel’s G41 Express integrated graphics chipset. A cut below the G45 Express, the G41 can be found on cheaper motherboards whose prices should be closer to AMD’s expected norm for the 785G. The Pentium E6300 processor we’re using for testing on the Intel side is slightly more expensive than the Athlon II X2 250 that’s running the show for the 785G configs, which should even things out some.

Gigabyte’s G41-equipped G41M-ES2H

Because the EVO and UD3H have very different memory configurations, we’ve elected to use each to highlight a different aspect of the 785G’s performance potential. We’ve taken advantage of the EVO’s support for DDR3 memory by loading it up with 1600MHz DIMMs to see what the 785G can do with sideport video RAM and loads of system memory bandwidth. Since Gigabyte has taken a budget-minded approach with the UD3H, we’ve equipped that system with DDR2-800 memory to see how the 785G fares in a more modest configuration that’s also a better foil for the G41 Express.

We’ve made these configuration choices to explore the impact of memory speed on the 785G performance. Obviously, this gives the Asus board at an advantage, so we’ll be referring to the configurations by chipset when discussing memory, application, gaming, and video performance. The graphs have also been color-coded to make the DDR2-800 and DDR3-1600 785G results easy to pick out.

Although the OS isn’t yet available for sale, we’ve elected to use the Windows 7 RTM build for testing. Windows 7 supports the 785G’s dynamic power saving tech and AMD already has WHQL-certified drivers ready to go for the chipset.

All tests were run at least three times, and their results were averaged.

Processor

AMD Athlon II X2 250 3GHz


Intel Pentium E6300 2.8GHz
CPU/chipset link 2GHz HyperTransport 1066MHz FSB (266MHz
quad-pumped)

Motherboard
Asus M4A785TD-V EVO Gigabyte MA785G-UD3H Gigabyte GA-G41M-ES2H
Bios revision 0211 F1 F1

North bridge
AMD 785G AMD 785G Intel G41 Express

South bridge
AMD SB710 AMD SB710 Intel ICH7
Chipset drivers AHCI 1.2.0.125 AHCI 1.2.0.125 ???
Memory size 4GB (2 DIMMs) 4GB (2 DIMMs) 4GB (2 DIMMs)

Memory type


OCZ OCZ3G1600LV6GK DDR3 SDRAM
at 1600MHz


OCZ OCZ2G8008GQ DDR2 SDRAM
at 800MHz


OCZ OCZ2G8008GQ DDR2 SDRAM
at 800MHz
CAS latency (CL) 8 5 5
RAS to CAS delay (tRCD) 8 5 5
RAS precharge (tRP) 8 5 5
Cycle time (tRAS) 24 18 18
Command rate 1T 2T 1T

Audio codec
VIA VT1708S
with 6.0.1.7200 drivers
Realtek ALC889A
with 2.29 drivers
Realtek ALC888B
with 2.29 drivers
Graphics Integrated Radeon HD 4200
with 8.634.0.0
drivers
Integrated Radeon HD 4200
with 8.634.0.0
drivers
Integrated GMA X4500 with
15.15.0.64.1808
drivers
Hard drive
Western Raptor X 150GB
OS Windows 7 Ultimate RTM

Our test system was powered by an OCZ PowerStream 520W power supply unit.

We’d like to thank Western Digital for sending Raptor WD1500ADFD hard drives for our test rigs.

We used the following versions of our test applications:

The test systems’ Windows desktop was set at 1280×1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests.

All the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.

Memory performance

While it doesn’t define system performance, memory bandwidth can play an important role, particularly with integrated graphics platforms that must share bandwidth with an onboard GPU.

Thanks to the Athlon II’s on-die memory controller, the 785G configs have much higher memory bandwidth and much lower access latencies than the G41 Express. The difference between the two 785G setups isn’t as striking as one might expect given the 800MHz gap in memory clock speed, though.

The following graphs are a little indulgent, but they paint the latency picture in three dimensions, across multiple block and step sizes. I’ve arranged the graphs in order of highest latency to lowest. Yellow represents L1 cache, light orange is L2, and dark orange is main memory.

Yup, the 785G access latencies are impressively low, even with pedestrian DDR2.

Application performance

WorldBench usually fills in as our application test suite for chipsets and motherboards, but it doesn’t get along with Windows 7. Instead, we’ve used a small collection of application tests that cover three of the most demanding tasks encountered by modern PCs: video encoding, file compression and decompression, and image processing.

The 785G configs have meaningful edge over the G41 Express in the first pass of our x264 encoding test. And as one might expect, the DDR3 785G config is also faster than the DDR2 setup, although not by much.

Our x264 benchmark doesn’t take advantage of the potential general-purpose computing power housed within the Radeon HD 4200’s stream processors, so the results above are more a test of CPU and memory performance. We’ve yet to see applications designed to leverage GPU power for video transcoding match the output quality of traditional encoding software, though. GPU-accelerated transcoding currently seems more appropriate for converting video for playback at low resolutions on handheld devices.

Memory bandwidth plays more of a role in 7-Zip compression than it does with decompression. In both cases, however, the 785G system outruns the G41 rig.

The tables turn when we stitch together a four-photo panorama shot of Damage Labs. Here the G41 system performs the stitch operation a few seconds faster than the quickest 785G config.

Gaming

A lack of GPU horsepower confined us to relatively low resolutions and detail levels for our gaming tests. That’s the price you pay for integrated graphics. We used built-in benchmarking functions to test Left 4 Dead and Far Cry 2 before switching to FRAPs for the remainder of our gaming tests. When using FRAPs, we recorded five 60-second gameplay sessions to ensure that our results were consistent and repeatable. Average and median low frame rates have been reported for the games we, er, FRAPsed.

Although the G41 isn’t all that far behind in some games, it’s clearly in a different league than the 785G. And while the 785G didn’t exhibit any compatibility problems or visual anomalies, the G41 suffered from both. GRID simply wouldn’t run on the G41 Express, and in Battlefield Heroes, in-game grass was obviously rendered incorrectly.

The 785G obviously fares better with sideport DRAM and faster system memory, but it’s only notably faster in a couple of games. In fact, the performance gaps are greatest with older game engines, suggesting that GPU power more than memory bandwidth bottlenecks the Radeon HD 4200’s performance with newer titles.

Blu-ray playback

We conducted our Blu-ray playback tests across three high-bitrate movies covering the major formats available on the market. 28 Days Later was used to represent the H.264 camp, Nature’s Journey for VC-1, and Click (which it pains me to even admit that we purchased on Blu-ray) for MPEG2. The latest version of PowerDVD, which supports the decode acceleration built into both the 785G and G41 Express, was used for testing.

Playback was run full-screen over HDMI at 1080p resolution, a setup that initially proved a little problematic for the 785G configs and my Dell 2408WFP LCD monitor. At 1080p, the video output of both the Asus and Gigabyte boards was a little discolored, with blurry text to boot. All was crystal clear at 1920×1200, however. That’s the native resolution of the display, but the G41 Express had no problems outputting a sharp picture at 1080p on the same monitor.

It appears this problem is specific to the 2408WFP. I just took delivery of a Dell S2409W LCD, and at its native 1080p resolution, 785G output over HDMI looks good.

Intel may support decode acceleration for all three Blu-ray formats on its more expensive G45 Express chipset, but the G41’s decode assist is limited to MPEG2 content. At least it’s quite effective there, delivering lower CPU utilization than either 785G config.

The 785Gs have lower CPU utilization with VC-1 and H.264 playback, with the latter proving particularly demanding of the G41 config. It appears that additional memory bandwidth helps to lower the 785G’s CPU utilization during Blu-ray playback, as well. This difference is most pronounced with Nature’s Journey, a 1080i title that we’ve previously seen be very CPU-hungry on systems with pokey memory bandwidth.

Of course, I should note that all three systems had no problems smoothly playing back all of the movies we tested. Even today’s budget dual-core processors can handle HD video playback without the assistance of dedicated decode acceleration logic.

Serial ATA performance

Now begins our look at peripheral performance. Since the Asus and Gigabyte boards share the same SB710 south bridge component, there’s no need to present results for both of them, especially since memory bandwidth tends not to play a role in targeted peripheral performance tests. The 785G results on the following pages were obtained with our DDR3 config.

The Serial ATA disk controller is one of the most important components of a modern core logic chipset, so we threw each platform a selection of I/O-intensive storage tests using a Western Digital VelociRaptor.

IOMeter

We’ll begin our storage tests with IOMeter, which subjects our systems to increasing multi-user loads. We used IOMeter’s workstation and database test patterns, since those are more appropriate for desktop systems than the file or web server test patterns. This particular test makes good use of the Native Command Queuing capability built into the AHCI specification. However, the G41 Express’ ICH7 storage controller doesn’t support AHCI, putting it at a bit of a disadvantage, at least in theory. AMD has a history of horrible AHCI drivers that, as recently as two months ago, were essentially broken in Windows Vista.

And they’re apparently broken in Windows 7, too. After seeing the 785G barely outpace the NCQ-less G41 Express, we tested the AMD platform again using Windows 7’s integrated AHCI drivers. As you can see, they deliver much higher transaction rates than AMD’s own drivers.

The Windows 7 drivers do consume more CPU cycles, but that’s to be expected under the circumstances. They’re doing more work, after all.

HD Tach

We used HD Tach 3.01’s 8MB zone test to measure basic SATA throughput and latency.

The G41 Express fares a little better than the 785G in HD Tach’s burst speed test. There’s no difference in sustained transfer rates between the two, though.

Given HD Tach’s +/- 2% margin of error in the CPU utilization test, it looks like the 785G and G41 are on essentially equal footing here.

USB performance

Our USB transfer speed tests were conducted with a USB 2.0/Firewire external hard drive enclosure connected to a 7,200-RPM Seagate Barracuda 7200.7 hard drive. We tested with HD Tach 3.01’s 8MB zone setting.

The 785G proves a little slower than the G41 when reading, but it’s faster with writes. Of course, the AMD chipset also consumes more CPU cycles. Even with HD Tach’s margin of error in the CPU utilization test factored in, the G41 is still more efficient.

PCI Express performance

We used NTttcp to test PCI Express Ethernet throughput using a Marvell 88E8052-based PCI Express x1 Gigabit Ethernet card.

PCI performance

To test PCI performance, we used the same NTttcp test methods and a PCI Intel GigE NIC.

Although the G41 Express offers consistently higher throughput and lower CPU utilization with both PCI and PCI Express Gigabit Ethernet cards, the performance gaps are pretty narrow, all things considered.

Power consumption

That covers the chipset-specific portion of today’s festivities. Now it’s time to switch gears to exploring variables more dependent on motherboard attributes than core-logic components. First up we have power consumption tests. Here we measured system power consumption, sans monitor and speakers, at the wall outlet using a Watts Up Pro power meter. Readings were taken at idle and while playing back an H.264 Blu-ray movie, 28 Days Later. Results that fall under “No power management” were obtained with Windows 7 running in high-performance mode, while those with power management enabled were taken with the OS in its balanced performance mode.

While the G41 Express system pulls the fewest watts at idle, the difference in power consumption between the two 785G boards is actually more interesting. The UD3H proves more frugal with and without Windows 7’s balanced power plan enabled, making me wonder if the Asus board’s extra power phases might be the culprit.

With a Blu-ray movie playing, the G41’s power consumption jumps into the same ballpark as the others. That platform’s higher CPU utilization during H.264 playback is certainly a factor here, nicely illustrating the benefit of decode acceleration even if you have enough CPU horsepower to handle the task without it.

Interestingly, the EVO consumes slightly less power than the UD3H here, at least under the balanced power profile. For what it’s worth, Asus does have EPU software that’s supposed to lower system power consumption. However, we found that this app only produces meaningful reductions in power consumption if you allow it to cap the CPU’s clock speed below its default value, costing precious performance in the process.

Overclocking

If you’re going to get an AMD-based system, we generally recommend Black Edition processors because their unlocked upper multipliers facilitate easy overclocking. The Athlon II X2 250 CPU we used for testing has its multiplier capped at 15X, forcing us to resort to ramping up the system’s base clock to increase the CPU speed.

Since our focus is on motherboards here, we first lowered the CPU and memory multipliers to take those components out of the equation. Next, we cranked the base clock, testing stability along the way with Prime95.

The EVO managed to hit a 230MHz base clock with little fuss, but it wasn’t comfortable above that speed. We tried increasing various system voltages and even fiddling with the HyperTransport multiplier, but neither ensured stability under load.

Gigabyte’s UD3H was more comfortable when pushed, sailing up to a 290MHz base clock without the need for voltage or multiplier tweaks. However, the board wouldn’t post with a 300MHz base clock, and it even corrupted the BIOS in the process. Thanks to Gigabyte’s DualBIOS system, the board automatically fixed itself and was up and running again in no time.

Motherboard peripheral performance

Core logic chipsets integrate a wealth of peripherals, but they don’t handle everything. Firewire, Ethernet, and audio are farmed out to auxiliary chips, for example. To provide a closer look at the peripheral performance you can expect from the motherboards we’ve tested today, we’ve compiled Ethernet, Serial ATA, USB, Firewire, and audio performance results below.

HD Tach
Firewire performance

Read burst

speed (MB/s)


Average read

speed (MB/s)


Average write

speed (MB/s)


CPU utilization

(%)


Asus M4A785TD-V EVO
8.5 8.3 5.7 2.0

Gigabyte MA785G-UD3H
41.0 35.5 17.0 5.7

The EVO’s VIA Firewire controller is painfully slow when compared with the Texas Instruments chip on the Gigabyte board. You don’t see the G41M-ES2H listed here because it doesn’t have Firewire onboard.

HD Tach
USB performance

Read burst

speed (MB/s)


Average read

speed (MB/s)


Average write

speed (MB/s)


CPU utilization

(%)


Asus M4A785TD-V EVO
31.4 30.6 27.0 13.3

Gigabyte G41M-ES2H
33.9 32.6 29.8 3.7

Gigabyte MA785G-UD3H
31.7 30.2 28.7 16.3

As one might expect, the Asus and Gigabyte 785G boards are closely matched in our USB performance tests.

HD Tach
Serial ATA performance

Read burst

speed (MB/s)


Average read

speed (MB/s)


Average write

speed (MB/s)

Random access time
(ms)

CPU utilization

(%)


Asus M4A785TD-V EVO
242.5 109.8 80.7 7.1 5.3

Gigabyte G41M-ES2H
253.3 109.8 80.9 7.1 3.3

Gigabyte MA785G-UD3H
230.6 109.7 83.5 7.2 8.0

They’re within striking distance of each other when we switch to a Serial ATA drive, as well.

NTttcp Ethernet
performance
Throughput (MBps)
CPU utilization
(%)

Asus M4A785TD-V EVO
941.7 16.8

Gigabyte G41M-ES2H
724.5 14.3

Gigabyte MA785G-UD3H
940.0 29.0

There’s quite a gap when we look at Gigabit Ethernet CPU utilization, however. The Gigabyte 785G board’s RTL8111C GigE chip has a history of higher CPU utilization, while the Asus board makes use of an apparently more frugal RTL8112L. At least both offer competitive throughput.

RightMark Audio
Analyzer audio quality

Overall score

Frequency response

Noise level

Dynamic range

THD

THD + Noise

IMD + Noise

Stereo Crosstalk

IMD at 10kHz

Asus M4A785TD-V EVO
3 4 3 3 4 2 1 4 1

Gigabyte G41M-ES2H
4 5 4 4 5 3 5 5 5

Gigabyte MA785G-UD3H
4 5 5 5 3 2 3 5 3

Thanks to its real-time encoding capabilities, the UD3H’s integrated audio implementation is already superior to that of the EVO for multi-channel digital output. According to a 24-bit/192kHz RightMark Audio Analyzer test looped from each board’s front-channel output to its line input, the Gigabyte offers better analog signal quality, as well.

Conclusions

The 785G is undoubtedly an important integrated graphics chipset, particularly as we enter the back-to-school season and anxiously await Windows 7’s launch, but I’m finding it hard to muster what feels like an appropriate level of excitement. Yes, the 785G will find its way into droves of budget systems powered by Microsoft’s latest operating system. And yes, enthusiasts will probably snap up a good number of boards to build home theater PCs for themselves or basic desktops for friends and family. But the 785G isn’t a radically new product. The integrated Radeon HD 4200 isn’t much of an upgrade over the old 3200, and it’s still woefully inadequate if you want to play the latest games at reasonable resolutions and detail levels. AMD hasn’t fixed its south bridge AHCI drivers, allowing the plague of poor Vista and XP performance scaling to infect Windows 7. Support for multi-channel LPCM output over HDMI hasn’t been added, either, despite the fact that integrated graphics chipsets from Intel and Nvidia are both up to the task. Really, beyond some new features for the UVD and support for Socket AM3 processors, little has changed since the 780G.

I suppose I’m not looking at the 785G from the proper angle, though. This is a budget chipset meant for $80 motherboards, so it’s probably not meant to dazzle with new hotness. Instead, the 785G does what a modern budget chipset should: it combines more than enough I/O connectivity for the average user with a competent graphics core that can easily handle light gaming and high-definition video playback. Add in WHQL-certified drivers for Windows 7 months before the operating system’s official release, and you have a solid foundation for just about any system short of a gaming rig.

So the 785G is a subtle refinement of the 780G, one that hasn’t addressed some of the rough edges of the original. But then the 785G isn’t exactly entering a market teeming with stiff competition. The only integrated graphics chipset that I can think of that’s more capable than the 785G is Nvidia’s GeForce 9300, but it’s a bit of a power hog and nearly impossible to find on sub-$100 mobos. If you want to build a system with integrated graphics on the cheap, the 785G really is your best bet.

As for the motherboards we’ve looked at today, the Asus MA785GTD-V EVO and Gigabyte MA785G-UD3H both offer commendable flexibility, sporting not only integrated graphics processors, but also the ability to run two-way CrossFire configs. I think that also makes the boards a little confused, but it’s hard to complain about having more options. After all, the presence of these full-sized ATX models isn’t going to dampen the number of more focused Micro ATX designs based on the 785G. Plus, both have solid layouts and decent arrays of BIOS-level overclocking and tweaking options.

Gigabyte MA785G-UD3H
August 2009

But which one is best? That’s an easy call, actually. The UD3H is $10 cheaper, yet it has the best audio feature set, a much faster Firewire chip, lower idle power consumption, more PCIe slots, and support for older processors and DDR2 memory. Sure, DDR3 prices have fallen dramatically over the last year, but DDR2 is still less expensive. When you’re dealing with budget systems, every dollar counts.

To Asus’ credit, the EVO is a faster 785G implementation than the UD3H, in part thanks to its 128MB of sideport memory. Speed isn’t the only consideration at this end of the spectrum, though. The UD3H is a better all-around board, and although I wouldn’t put one in my primary desktop, it’d be just about perfect for my next home theater PC. For me, that’s good enough for Editor’s Choice distinction.

Comments closed
    • SpeedyVV
    • 10 years ago

    I used the 785G and a Atlhon II X2 245 to build a HTPC and could not be happier.

    Running 1080p just fine.

    • VILLAIN_xx
    • 10 years ago

    Hmm, you guys really love newegg and newegg really loves you.

    Thats the first time ive seen Newegg say in bright red r[<"Winner of a Techreport editor's award"<]ras a product description. haha.

    • todd
    • 10 years ago

    Nice, but I think I’ll hold on to my gigabyte 690g/5000 black for a while longer.
    I’d like an igp board with ddr3, sata3, and usb3.
    Waiting also gives the side benefits of better/cheaper processor and ram. SSD drives might just be reasonable by that time as well.
    Possible small form factor/low power options might also make me hesitate.
    I will likely wait till Q2, possibly even Q3, of next year.

    • clone
    • 10 years ago

    while the poor AHCI isn’t world altering, I wonder if it’s time to notify AMD that it will be getting more notable mention after all of this time remaining broken.

    it’s one thing to have a bug that is fixed in the next revision it’s quite another to have the same bug remaining unfixed after mutiple chip revisions.

    yes I know it’s not serious and won’t affect the vast majority of users but c’mon already fix it…….if it makes it into the 8xx south bridges I’ll stop recommending AMD products on the whole, enough is enough already.

    • internetsandman
    • 10 years ago

    I wish they had compared this to the geforce 9300 as well. I realize it’s not quite the same budget area, but I think it’d be a much better comparison than any integrated intel graphics chipset.

    • Dissonance
    • 10 years ago

    There’s been some confusion over whether the 785G supports multi-channel LPCM audio output over HDMI. Our review initially indicated that it did, but that information is incorrect. Like its forebear, the 785G can only output stereo LPCM audio over HDMI.

    We’ve updated the review to correct the error, although it doesn’t change our overall conclusions on the chipset or either motherboard.

      • Kurotetsu
      • 10 years ago

      The exact same thing happened in Anandtech’s review of the chipset. Seems of bizarre to leave such an important feature (for the people most likely to use this board) out. Though, I get the impression its more software than hardware related?

    • demani
    • 10 years ago

    Is it usable with Hulu and Netflix streaming at 1080p? HTPC users want to know!

      • MadManOriginal
      • 10 years ago

      Hulu has little to do with the chipset and any CPU that will work in these mobos is more than capable. I’m not sure what Netflix requires but if an XBox can stream it I certainly hope one of these could.

      • Skrying
      • 10 years ago

      Assuming you put the right CPU in there, yes. No video graphics chip can accelerate Flash video, which is what Hulu and Netfix are.

        • Palek
        • 10 years ago

        Actually, Netflix – on the PC – uses Silverlight.

        -[

    • flip-mode
    • 10 years ago

    I’ve been digesting this review all day, and I finally gotta say that Geoff sang true when he said:

    q[

    • d0g_p00p
    • 10 years ago

    Damn, that Asus board has NOS, twin turbo’s and spoiler? Someone needs to stop watching The Fast and the Furious before designing motherboards.

    • eric93se
    • 10 years ago

    I don’t see the PSU used? Anyone know?

      • Dissonance
      • 10 years ago

      OCZ PowerStream 520W. I’ve updated the testing methods section, as well.

        • eric93se
        • 10 years ago

        Wow so this PSU is rated at 63% efficient at max load! I bet a cheap Antec Basiq would used 20-25W less power! Why in the world would you build a modern PC with a PSU from ~2005

          • Meadows
          • 10 years ago

          It never hit max load.

    • Lazier_Said
    • 10 years ago

    I think this review benching against G41 is missing the point. Brand new RV620 against.. Intel’s oldest, cheapest, and widely known as slowest in class G41/X4500.

    More interested to see how 785G stacks up against 780G, 790GX, GF8000, G45, etc.

      • lex-ington
      • 10 years ago

      Actually, it was on point.

      We’re comparing a price point. The G41’s are in the 785G’s price range. The G43’s aren’t really saying much and the G45 starts at around $95 and goes up rather quickly.

      Would you rather get a 785G/XII – 250 for $159 or a G45/E6300 for $179? And that’s using boards thet people would actually buy. Yes, ECS may be cheaper, but would you buy them?

        • Lazier_Said
        • 10 years ago

        That’s exactly the point, after reading this article I don’t know which of those I’d get because the only comparison numbers I saw were for the craptastic G41. Which I already knew wasn’t competitive with anything.

          • poulpy
          • 10 years ago

          AFAIK they both use the same GMA X4500 base, the only meaningful difference will be a lower CPU usage when decoding 1080p MPEG2 IIRC.
          As a general rule Intel specialises in crapastic IGPs, so unless you don’t care about anything beyond internet/emails and watching the odd movie just stay well clear of them, easy to remember.

    • hermanshermit
    • 10 years ago

    But which one is best? That’s an easy call, actually. The UD3H is $10 cheaper, yet it has the best audio feature set, a much faster Firewire chip, lower idle power consumption, more PCIe slots, and support for older processors and DDR2 memory.

    – Indeed, a fabulous upgrade path for budget PCs. I have a 2 year old 690G (AM2) board with a 45w X2 and DDRII. This is a really sweet and cheap upgrade for a HTPC/light gaming living room PC. I can even go for a 45Wx4 core CPU when funds allow (actually, really, more as “needs” allow) and hand down the complete 690G/X2 innards which will still be a good surfing email machine for a good few years.

    I would however like to see a mATX or even mini ITX version of this board, preferrably with integrated power that will run off a 12-19.2V brick. I don’t think many people in this market are going to need much in the way of slot expansion.

    The only gripe really is it would have been nice to hold off and offer USB3 in a new chipset.

    As for the article, why no testing of graphics overclocking (50%+ was easily attainable on 780G and some managed nearly 100%) and no testing of UVD2 and what it can do with regards to image enhancements and scaling – the quality of this is probably even more important for the very near future than true HD ability. Toshiba do a nice range of DVD players that have superior scaling and enhancement and they make a huge difference to the enjoyability of SD on the ubiquitous HD panels in people’s homes.

    • Hattig
    • 10 years ago

    I got to the overclocking section and was sad to see that the internal graphics weren’t overclocked.

    Otherwise, it seems a good budget chipset without the graphical issues of Intel’s offerings.

    • WillBach
    • 10 years ago

    Thanks for testing the analogue audio, Geoff, and warning us that the Via audio chipset doesn’t support real-time Dolby decoding. Could you tell us if the audio over the HDMI port supports Dolby decoding? Does it even provide audio at all? Thanks!

    • Shobai
    • 10 years ago

    couldn’t tell if this’d been reported before, but under PCI express performance, the first graph seems to have either the names or colours swapped.

    great review =) definitely keen on µATX versions, though!

    • ntimid8r
    • 10 years ago

    When Gigabyte first started using that layout, they would cut the x4 slot down to x1 when using the bottom 2 x1 slots as the lanes were shared by all three slots. They don’t document this with the newer boards so it may be that the bottom x1 slots are being served by the sb710. However they do it, the fact that they do has been the reason my last 3 motherboard purchases have been Gigabyte ATX boards.

    • juampa_valve_rde
    • 10 years ago

    looks in a bit better shape than 780g, pushed to use sideport, hdmi 1.3, and sb710 (acc & core unlocking on a cheap board, yeah!). now there’s no reason to buy 790gx (other than crossfire 2×8). dx 10.1 just smells like marketing gimmick for an igp.

    that thing of ahci drivers is awful, but also knowing both win vista and 7 had integrated a decent driver then there is no big deal, just install catalyst for video and done.

    • setzer
    • 10 years ago

    I have a different opinion on the benefits of using windows AHCI drivers instead of ATI’s ones. In my tests and from actual usage, the windows AHCI drivers, consume too much cpu for no gain, at least on my hard drives. Instead ATI’s drivers improved burst rate and lowered the cpu utilization to decent values while the averaged read values are the same.

    I’ll post my results on my 780G/SB700 (win vista x64 business SP2, Athlon X2 4050e, 4gb DDR2@800):

    *[

      • just brew it!
      • 10 years ago

      In Geoff’s tests the CPU usage peaked at ~4% with the Microsoft driver, which isn’t bad. I wonder why your CPU usage was so high?

        • setzer
        • 10 years ago

        Probably faster cpus get the work done faster. Even in the original review of the 780G a faster atlhon x2 was used.
        And you really notice the high cpu usage, at least in my case, when you are moving files between two different physical drives (say several gbs worth of anime ~200/300MBs a piece).
        For reference my motherboard is the same as the one reviewed here in techreport, the Gigabyte GA-MA78GM-UD2H (rev. 1.0).
        Things i would like to mention are: my SATA mode is set as AHCI in bios and that the default windows drivers show my SATA drives connected to an IDE controller.
        And that ATI’s driver solution to the AHCI is far from perfect, first you need to install the southbridge drivers and, for no particular reason, you also need to install the RAID drivers (even if you aren’t using RAID) to get AHCI functionality, the downside of this all is that if you are using AHCI you lose smart data on your drives.

        And why would someone without an RAID array install the RAID drivers is beyond me…

    • Tamale
    • 10 years ago

    I still wanna know more about this southbridge bug. Is it bad enough for me to be an idiot to consider this for my new desktop build?

      • Prototyped
      • 10 years ago

      I think it’s a non-issue. The out-of-box Windows 7 and Vista AHCI drivers work just fine with the southbridge, it’s just the vendor drivers from AMD (and bundled by the motherboard vendors) that cause subpar performance.

      Which you can avoid by, you know, just not installing them.

      It’s not like they add any functionality you don’t already have by using Microsoft’s excellent driver. In my experience Microsoft’s generic drivers tend to be more stable and less buggy than vendor drivers anyway, a result of the fact that hardware vendors couldn’t write decent software to save their lives, not even Intel.

      The hidden issue is the CPU utilization of the USB drivers, really. Note how both SB710 boards use 4 times as much CPU time as the ICH7 USB driver.

      As far as ICH7 AHCI is concerned, Intel doesn’t have support for AHCI in their ICH7 “Base” driver, but if the motherboard manufacturer exposes AHCI in the BIOS, Windows Vista and 7’s generic AHCI driver by Microsoft can be used for the device. (And for Windows XP, the Intel AHCI driver’s .inf can be modified to add the PCI product ID and loaded during the installation process.)

        • just brew it!
        • 10 years ago

        Agreed. The performance appears to scale just fine with the Microsoft driver, so as long as you make sure you don’t use ATI’s SATA driver you should be fine.

        As an aside, from the performance scaling graph I’d say the issue is that they haven’t implemented NCQ properly. It looks suspiciously similar to (though just slightly better than) the non-NCQ controller.

    • Rza79
    • 10 years ago

    quote: /[

    • Fighterpilot
    • 10 years ago

    Unless you have a rig that is pimped out with more windows than Madman’s infallible XP install has open at one time,I don’t see how the color scheme of the mobo has any place in buying decisions.

    • kenclopz
    • 10 years ago

    Christ! Who could have imagined this video chipset power when we were looking not too long ago at S3 chipsets and x300 chipsets. I must say, I am truly impressed that a chipset can play Left 4 Dead at 1280×720 (HD quality) at reasonable framerates. For HTPC users, this is an awesome indicator as one day we’ll be able to build an HTPC that can play all games at HD quality (1280×720) without the need for a large video card. The size of the good HD HTPC will shrink invariably.

    Cheers to progress!

    Also, I can’t believe I can play Tekken 2 and Time Crisis 2 on my new Verizon Rival cellphone. Who needs a DSI or an iphone? I can take 2 megapixel photos, listen to mp3’s, make calls, and play 3D games on my cell phone. All with a sms keyboard.

    Loving life. Yeah, digital age is the shiznatt!

      • TravelMug
      • 10 years ago

      True. I think a lot of games are playable on these boards. Have a few crappy old PCs with X300SE in them for a bit of CoD4 action. Lowest settings and 640×512 (created through PowerStrip) to have simple scaling for the 1280×1024 LCDs, but takes nothing away from playability. And this 4200 is way more powerfull than those old cards.

    • MadManOriginal
    • 10 years ago

    Geoff- could you perhaps enlighten us on the i[

      • solgoldberg
      • 10 years ago

      None of the current AMD SB7XX devices have PCIe lanes for add-in cards.

      Some of the x1 connectors share PCIe lanes with the PCIex16/4 connector. The Gigabyte manual states:

      “The PCIEX1_2 and PCIEX1_3 slots share bandwidth with the PCIEX4_1 slot. When the PCIEX4_1 slot is populated with a x4 card, the PCIEX1_2 and PCIEX1_3 slots become unavailable.”

    • Skrying
    • 10 years ago

    mATX, please.

    • TheEmrys
    • 10 years ago

    There’s no mention of the Crossfire X. Looks like an awfully good board for an HTPC.

      • Flying Fox
      • 10 years ago

      Needing a discrete card to get multi-channel LPCM can still be a deal breaker for some.

      I’m just glad that I bit the bullet and got myself a 4550 with HDMI, but for people who would mind an extra $40 for a discrete card, this can be a problem.

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