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Updated: AMD 785G: The Venerable 780G, Evolved
By ,
1. Introduction

Ed.: After discussing with AMD earlier today, it would seem that eight-channel LPCM is not one of the features present in 785G. As a result, we've made a couple of edits to the original story, while you'll find on this page, and page three. Overall, our assessment of 785G does not change. However, true HTPC enthusiasts will likely want to reconsider 785G if software-decoded Dolby TrueHD or DTS-HD MA is a buying requirement.

Since the beginning of last year, integrated graphics processors (IGPs) have become a lot more exciting. Consumers now have solid options from all of the major players, including AMD’s 780G/790GX, Intel’s G45, and Nvidia’s 8200/9300/9400. All of these components have their respective strengths and weaknesses, but compared to past offerings, these chipsets are light-years ahead.

Now, AMD is bringing a new product to the table, and the fresh 785G chipset is an evolution of the 780G; certainly not revolutionary. It was created to address some of the features that the 780G lacked, such as eight-channel LPCM audio over HDMI, picture-in-picture video acceleration, ATI Stream technology support, DirectX 10.1, and Windows 7 compatibility. In addition, AMD promises lower power usage with the 785G. None of these features represent a "killer app" for the company, especially since the competition already offers most of these capabilities in their existing products. But taken as a whole, the 785G is a very positive step in the right direction. That is, of course, assuming it can deliver the goods, which our testing will flesh out.

The State of IGP

While Intel's G45 for Socket 775 is over most of its teething problems and can playback a Blu-ray disc in a competent fashion, it isn't very impressive in the graphics department. Nvidia's 8200 for Socket AM2+ isn't much better when it comes to 3D horsepower, but Nvidia has addressed that weakness with its GeForce 9300/9400 chipsets for Socket 775. As far as AMD’s portfolio goes, the 780G is a fantastic low-budget chipset, and the 790GX is a solid midrange offering. With these products leading the IGP segment when it comes to price/performance superiority, why change the 780G now?

Perhaps AMD's best reason to introduce the 785G chipset isn't the chipset itself, but its new Phenom II-based processors that can be used with it, including the Athlon II. While the original Phenom was somewhat anemic compared to Intel's Core 2 offerings (and was stigmatized early on for its TLB issue), the Phenom II sports a more refined architecture that has returned AMD to price/performance leadership with some of its parts.

With this in mind, there probably isn't a better time to re-introduce the improved 785G as an alternative to Nvidia's 9300/9400, and to highlight the 785G's strengths over Intel's G45.

2. 785G Northbridge And SB710 Southbridge Vital Statistics

Let's have an overall look at the 785G and its brethren to see how their vital statistics stack up:

Northbridge

AMD 785G AMD 780G AMD 790GX
Processor Interface HT 3.0/5,200 MT/s HT 3.0/5,200 MT/s HT 3.0/5,200 MT/s
PCI Express Support 2.0/26 lanes/1 x 16 Graphics 2.0/26 lanes/1 x 16 Graphics 2.0/26 lanes/2 x 8 Graphics
Integrated Core RV620 RV610 RV610
DirectX/OpenGL 10.1/2.1 10.0/2.1 10.0/2.0
Shaders/TU/ROP
40/4/4
40/4/440/4/4
Graphics Clock 500 MHz 500 MHz 700 MHz
Display Outputs DisplayPort, HDMI 1.3, DVI, VGA DisplayPort, HDMI 1.2, DVI, VGA DisplayPort, HDMI 1.2, DVI, VGA
Multi-GPU Hybrid CrossFireX Hybrid CrossFireX Hybrid CrossFireX, CrossFireX
Addtl. PCIe Six x1 PCIe 2.0 Six x1 PCIe 2.0 Six x1 PCIe 2.0 



Southbridge SB710 SB700/SB710 SB750
Interconnect A-Link Xpress (4 x PCIe 1.1) A-Link Xpress (4 x PCIe 1.1) A-Link Xpress (4 x PCIe 1.1)
RAID Support RAID 0, 1, 10 RAID 0, 1, 10 RAID 0, 1, 10, 5
Audio HD Audio HD Audio HD Audio
USB 12 USB 2.0 + 2 USB 1.1 12 USB 2.0 + 2 USB 1.1 12 USB 2.0 + 2 USB 1.1
Ethernet N/A N/A N/A

There aren't any super-significant differences between 780G and 785G as far as raw specifications are concerned, save DirectX 10.1 support for the new 785G. Keep in mind that the 785G does have some features that the 780G and 790GX do not have, which we'll go over in the next few pages.

The higher-end 790GX differentiates itself from its brothers with a higher 700 MHz graphics clock, the ability to use dual discrete graphics cards in CrossFireX, and the additional RAID 5 mode. All of these boons are missing from the new 785G, indicating that the 785G is not positioned as the next big thing, but as an improved replacement for the 780G chipset. Pricing will likely fall to current 780G levels over time, and while AMD admits that its customers will still be able to purchase the 780G chipset should they choose to do so, 785G will slowly replace 780G. Perhaps we'll see a 795GX chipset arrive in the not-too-distant future, bringing the 785G advancements to the higher-end 790GX price segment.

The SB710 Southbridge

The SB710 is nothing new. It has already been used in conjunction with the 780G as a replacement for the older SB700 chipset component. The SB710 is something of a hybrid between the older SB700 and the SB750 commonly used on 790GX-based boards. And, like the SB750, SB710 sports Advanced Clock Calibration (AAC), used to enable additional headroom in Phenom processors (but no longer needed with Phenom II).

Like the SB700, however, AMD's SB710 does not support RAID 5, although it does support RAID 0, 1, and 10 arrays.

3. Features For The Home-Theater Crowd

Let's have a look at the 785G's new features and how these might benefit the end user.

Eight-channel LPCM audio support over HDMI (Updated)

Ed.: Having just discussed this issue with AMD, it appears that 785G was never claimed to include eight-channel LPCM. Rather, this was a mistaken assumption given the Radeon HD 4200-class GPU and HDMI 1.3 feature update (versus 1.2 for 780G) exacerbated by the fact that we didn't have a stereo receiver on-hand to actually test whether the feature was actually working. In fact, AMD says the chipset's audio block has not changed at all since the 780G. We've updated the complete review where it was needed, apologize for the mis-information, and promise diligence in the future. For anyone running six-channel audio setups, digital audio output is still able to pass encoded Dolby Digital/DTS, just as the 780G was able to do.

Arguably, the most compelling feature for the hardcore home-theater enthusiast is eight-channel LPCM uncompressed audio support over HDMI. As it turns out, the 785G does not offer this functionality.

There has been some conflicting information released about this feature. AMD even mentions it on the 785G chipset overview page on their Web site:

To AMD's defense, footnote 3 mentions that "Full enablement of some ATI Avivo™ HD capabilities may require complementary products." However, the sentence including "HDMI with 7.1 audio surround sound support" does not reference footnote 3, instead referencing footnote 4: "Not all features will be supported on all machines. Check with your PC manufacturer for specific model capabilities and supported technologies."

Regardless, the important thing is that we clarify that the 785G does not support eight channel LPCM over HDMI, as originally stated.

While the Intel G45 and Nvidia 8200/9300/9400 chipsets have supported this feature since their release, AMD's 780G/790GX have been limited to two-channel LPCM over HDMI. This is somewhat ironic, since AMD's Radeon HD series of discrete video cards supported eight-channel LPCM over HDMI before these IGPs came to market.

I have a confession to make: I am not an audiophile. I listen to regular MP3s and think they sound great, so I don't have much of a problem with standard Dolby Digital/DTS. I don't own an HDMI amplifier and make due with the optical connection on Logitech's Z-5450 speaker system, which I inappropriately use in my home theater. It is because of this that eight-channel LPCM doesn't excite me all that much. Even the previous 780G chipset could handle six channels (5.1 sound) of audio using Dolby Digital or DTS and simulate eight channels using a matrix algorithm such as DTS Neo6 or Dolby Prologic IIx. Sure it's lossy, but the difference is hardly perceptible to a guy like me.

Having said that, I can appreciate the audiophile's desire to have access to eight-channel Dolby TrueHD or DTS-HD. Unfortunately for these folks, the 785G is not what we had originally hoped for, as it turns out, it's limited to the same two channel LPCM over HDMI audio as its 780G/790GX predecessors.

It is for this discerning crowd that the 785G chipset offers eight channels of discrete uncompressed audio, which gets decoded by your software player of choice, down-sampled to CD-quality audio due to rights management restrictions and a lack of protected audio paths, and output as linear PCM.

For eight channels of discrete uncompressed audio (decoded by software, downsampled to CD quality due to DRM and a lack of a protected audio path, and output as linear PCM), the GeForce 9300/9400 and Intel G45 chpsets are the way to go. For more on our explorations check out parts one and two of our HTPC series. To this day, the only way to get true Dolby TrueHD or DTS-HD MA is through Asus' Xonar HDAV 1.3 doing pass-through over HDMI.

Video Detail Enhancements in UVD 2.0

The 785G has stepped up video quality with UVD 2.0, compared to UVD 1.0 in the 780G and 790GX chipsets. What this means is that the 785G chipset has the following four features that its predecessors do not:

Dynamic Contrast: Enabling this feature facilitates automatic adjustment of black and white levels for optimum contrast on the fly. Nvidia has offered something similar for a little while now, so it's only natural that AMD would add it to its portfolio of video quality enhancements. It is important to note that AMD warns against enabling the dynamic contrast feature, which it says can negate other image-quality enhancements, such as 3:2 pulldown, detail enhancement, and more.

Picture in Picture Acceleration: This feature will lower CPU utilization when dual video streams are being displayed at the same time. While dual video streams probably aren't a problem for modern low-end CPUs to handle, Nvidia's IGPs have offered this feature for some time. The 785G has the checkbox ticked as well, necessary for BD-Live compliance.

HD Flesh Tone Enhancement: This improves the appearance of skin color, ideally keeping it at natural hues.

HD Color Vibrance: This feature improves the vividness of color.

Features like these can make video enthusiasts weary, as dynamic enhancements have been known to arbitrarily over-saturate and over-contrast the video output. Fortunately, we have the option of leaving it off, so everybody wins.

4. Radeon HD 4200 Enhancements

For years now, we've wished that someone would come out with an IGP capable of handling today's games at reasonable detail settings and at resolutions of at least 1280x1024, which is the lowest resolution at which I'd be happy playing.

The Radeon HD 4200 built into AMD's 785G chipset is, unfortunately, not the realization of this dream.

Don't get me wrong. The 785G is a great IGP, but it's pretty much exactly as great as the 780G before it, as the performance-oriented specifications have remained essentially identical: 40 stream processors, four texture units, and four ROPs. The 785G even runs at the same clock speed as the 780G, 500 MHz.

So what's different abut the 785G graphics processor? DirectX 10.1 support is the obvious answer. And, well, not much more as far as hardware specifications go:

AMD 78x and 79x Graphics Processors

AMD 785G AMD 780G AMD 790GX
Integrated Core RV620 RV610 RV610
DirectX/OpenGL 10.1/2.1 10.0/2.1 10.0/2.0
Shaders/TU/ROP
40/4/4
40/4/440/4/4
Graphics Clock 500 MHz 500 MHz 700 MHz

As suggested by the name 785G, this is an incremental upgrade. The DirectX 10.1 enhancements will not offer any immediate performance benefits for the end-user. DirectX 10.1 features can be enabled, but these won't likely speed up the frame rates, as we will demonstrate in our game benchmarks.

While the chipset's 785G designation reflects minor improvements, the name of the Radeon HD 4200’s GPU is quite a bit more provocative. Given its name, one might assume that the Radeon HD 4200 (785G) is superior to the Radeon HD 3300 (790GX), which is not the case when it comes to gaming. The 790GX is clocked at 700 MHz, while the 785G is clocked at 500 MHz. And with everything else being pretty much equal, the 790GX is, of course, notably faster.

The bottom line is that the AMD 790GX and Nvidia GeForce 9400 remain the fastest gaming IGPs out there. As for the good news, most 780G or 785G chipsets should be able to overclock to 790GX specifications or a little higher without cooling modifications, so the end-user can experience passable 1024x768 gaming performance with a little tweaking. This is fine for the casual gamer, but discrete graphics remains the only solution for more demanding settings.

Things might get interesting in the next generation of IGPs if AMD integrates something similar to the Radeon 4350 with its 80 shader processors into a chipset, but I suspect we might not see that for a while yet, as it'll likely require a manufacturing shrink. And when that happens, the day's games will be more demanding and the cycle of pain will continue.

Note that some 785G-based boards will have an advantage over early 780G platforms, because they seem more likely to sport SidePort memory. The cache, consisting of 128 MB of DDR3, serves as dedicated video RAM for the IGP, boosting performance slightly. While some 780G motherboards do offer SidePort memory, it's much more common on the 790GX chipset.

5. Other 785G Goodies

AMD has a few more tricks up its sleeve with the 785G, including:

Lower Power Usage

It's hard to argue with lower power usage. AMD claims that the new Radeon HD 4200 IGP can dynamically scale IGP clock speeds based on usage requirements.

ATI Stream Technology

AMD's GPGPU solution is compatible with all Radeon 4000 series graphics processors, and that includes the integrated Radeon HD 4200. While both Nvidia and AMD make a lot of claims about processing all sorts of tasks on the GPU, there are precious few applications that take good advantage of either CUDA or ATI Stream.

It is interesting that we can now use an application that is optimized for both Nvidia's CUDA and AMD's ATI Stream to see which vendor’s IGP takes the best advantage of GPU acceleration. We'll try Cyberlink's Mediashow Espresso with the 785G chipset in addition to the GeForce 9300 chipset and see what happens. With no GPGPU solution of its own, Intel will have to sit this one out.

Windows 7 Support

Windows 7 has already hit RTM, and while it's nice to know that the 785G works with it out of the box, I'm not sure how many people are chomping at the bit to upgrade to an operating system the moment it's released. Still, there's certainly nothing wrong with timely Windows 7 support.

6. Hardware Choices, Setup, And Overclocking

When we were deciding what processors to use in this review, we wanted to up the ante a little bit. While AMD clearly preferred the new Athlon II 250 for testing, we thought it would be nice to go with something that had a little more kick. By purchasing a motherboard with an IGP, the end-user will save a lot of cash on graphics, so we'd like to see what a platform like this can do with the best, low-cost processor available.

We were able to find the Phenom II X2 550 Black Edition online for as low as $103. While this processor is similar to the Athlon II X2 250, it has two important things that the Athlon II does not have: 6 MB of L3 cache, and an unlocked multiplier. It even has a 100 MHz higher clock speed than the Athlon II X2 250. The downside will, of course, be higher power usage compared to the Athlon II, but we'll record the Athlon II's power usage in addition to the Phenom II X2 550 BE's to see the difference.

Having selected the Phenom II X2 as the AMD platform representative, we needed a similarly-priced Intel LGA 775 CPU. It turns out that there's not a great selection of Intel CPUs at the $100 price point, with the excellent Core 2 Duo E7400 (2.8 GHz/3 MB cache) retailing for about $120 and the Pentium E6300 (2.8 GHz/2 MB cache) going for $80. We decided to use a Core 2 Duo E7200 (2.53 GHz/3 MB cache) to represent the Intel camp. With more cache than the E6300 but a lower clock speed than the E7400, it accurately represents what Intel has to offer in the $100 range.

The only other platform specific choice was RAM. The new 785G motherboard is the only entry-level option in our test suite that uses DDR3 instead of DDR2,although the mid-range 790GX chipset also employs DDR3. To fairly compare the DDR2 and DDR3 motherboards in our benchmarks, we tried to find similarly priced 4 GB dual-channel RAM kits of both types; we settled on a DDR3-1333 kit with 9-9-9-24 timings, and a DDR2-800 kit with 4-4-4-12 timings.

As far as comparison platforms, for the AMD CPUs we tested a 790GX board (Asus M4A78T-E) and a GeForce 8200 board (ECS GF8200A). Because we didn't have a 780G board on hand, we underclocked the 790GX GPU to 500 MHz to simulate the 780G chipset for a separate set of game benchmark runs.

On the Intel side, we tested a G45 board (Asus P5Q-EM) and a GeForce 9300 board (Asus P5N7A-VM). We overclocked the 9300's GPU to 9400 specifications for all of our tests because we wanted to present the best possible GeForce 9400 scenario.

We used a beta driver for the IGP, but AMD assures us that publicly-available Catalyst drivers will arrive mid-August and will support the 785G. As mentioned above, Windows 7 drivers will ship with the boards at launch.

Overclocking the IGP

On our M4A785TD-M EVO motherboard, overclocking the IGP was a breeze.

When overclocking, there were only two settings for the IGP core: GPU clock speed and chipset voltage. We raised voltage up as high as we were comfortable with a passive heat sink on the northbridge, and our maximum GPU overclock was 850 MHz. With additional cooling to handle higher voltage, it's quite likely that there is more overclocking headroom on the 785G. Purportedly, 1 GHz isn't unheard of, but with the lowly passive heat sink, we backed down to a reasonable 800 MHz at 1.31 V over stock speeds.

We also tried to overclock the SidePort memory, as the M4A785TD-M EVO BIOS offered different memory-speed options and a slight memory over-voltage tweak, but we had no luck. Even with the smallest adjustment in SidePort memory clock speed, the display would corrupt.

However, the 300 MHz GPU overclock should show us some sizable gains in the game benchmarks and should at least take us past 790GX performance with its 700 MHz core clock.

7. Test System And Benchmarks
Test System Configuration
CPU

AMD: Phenom II X2 550 BE (3.1 GHz, 6.0 MB Cache)
Intel: Core 2 Duo E7200 (2.53 GHz, 3.0 MB Cache)

Motherboards

AMD 785G: Asus M4A785TD-M EVO
AMD 790GX: Asus M4A78T-E
GeForce 8200: ECS GF8200A
GeForce 9300: Asus P5N7A-VN
Intel G45: Asus P5Q-EM

RAM

DDR2: A-Data AD2800E002GOU (2 x 2 GB)
DDR2-800 at DDR2-800 CAS 5-5-5-18 2T

DDR3: G.Skill F3-10666CL7-2GBPK (2 x 2 GB)
DDR3-1333 @ DDR3-1338 CAS 9-9-9-24-33-1T

Graphics

Radeon HD 4200 (785G) - 500 MHz GPU
Radeon HD 3200 (780G)  - 500 MHz GPU (simulated using underclocked 790GX)
Radeon HD 3300 (790GX) - 700 MHz GPU

GeForce 8200 - 500 MHz GPU, 1.2 GHz shader
GeForce 9400 - 540 MHz GPU, 1.4 GHz shader (simulated using overclocked 9300)

Intel G45 - 800 MHz GPU

Hard Drive

Western Digital Caviar Black 640 GB
7,200 RPM, 32 MB Cache SATA 3.0 Gb/s

Sound

Integrated HD Audio

Network

Integrated Gigabit Networking

Power

Thermaltake Toughpower
1200W, ATX12V v2.2, EPS12V

Software

OS

Microsoft Windows Vista Home Premium x64 SP1

Graphics

GeForce 8200/9300: NVidia Forceware 190.38 WHQL
AMD 790GX: Catalyst 9.7
AMD 785G: 8.632-090626a-083962E Beta

Benchmark Configuration

3D Games

Left 4 Dead

Version 1014, Custom THG Benchmark
Test Set 1: Medium Settings, High paged memory
Test Set 2: Medium Settings, High paged memory, 2x MSAA, 8x AF

Crysis

Patch 1.2.1, DirectX 10, 64-bit executable, benchmark tool
Test Set 1: High Quality, No AA
Test Set 2: Very High Quality, 8x AA

Tom Clancy's H.A.W.X.

in-game benchmark
Test Set 1: Lowest Settings, DirectX 9
Test Set 2: Lowest Settings, DirectX 10

World in Conflict

Patch 1009, DirectX 10, timedemo
Test 1: High Details, No AA / No AF
Test 2: Very High Details 4x AA / 16x AF

Audio/Video Encoding

iTunes

Version: 8.1.0.52 (x64)
Audio CD ("Terminator II" SE), 53 min
Default format AAC

Lame MP3

Version: 3.98 64bits (07-04-2008)
Audio CD "Terminator II," 53 min.
wave to MP3

TMPGEnc 4.6

Version: 4.6.3.268
Import File: "Terminator 2" SE DVD (5 Minutes)
Resolution: 720x576 (PAL) 16:9

DivX 6.8.5

Encoding mode: Insane Quality
Enhanced multithreading enabled using SSE4
Quarter-pixel search

Xvid 1.2.1

Display encoding status = off

MainConcept Reference 1.6.1

MPEG2 to MPEG2 (H.264), MainConcept H.264/AVC Codec, 28 sec HDTV 1920x1080 (MPEG2), Audio: MPEG2 (44.1 kHz, 2 Channel, 16-Bit, 224 Kb/s), Mode: PAL (25 FPS)

Productivity

Autodesk 3ds Max 2009

Version: 11.0, Rendering Dragon Image at 1920x1080 (HDTV)

Gisoft AVG Anti-Virus 8.5

Version: 8.5.287, Virus database 2094, Benchmark: Scan 334 MB Folder of ZIP/RAR compressed files

WinRAR 3.80

Version 3.80, WinZip Command line Version 3.0, Compression = Best, Dictionary = 4,096 KB, Benchmark: THG-Workload (334 MB)

WinZip 12

Version 12.0, Compression = Best, Benchmark: THG-Workload (139 MB)

Sythetic Benchmarks and Settings

3DMark Vantage

Version: 1.02, GPU and CPU scores

PCMark Vantage

Version: 1.00, System, Memory, Hard Disk Drive benchmarks, Windows Media Player 10.00.00.3646

SiSoftware Sandra 2009 SP3

Version 2009.4.15.92, CPU Test = CPU Arithmetic / Multimedia, Memory Test = Bandwidth Benchmark

8. Benchmark Results: Synthetics

Let's begin with the usual suspects, Futuremark's 3DMark and PCMark suites. We should note that they didn't work on the 785G at first, but AMD sent us an updated .dll file that allowed us to run the benches. This is an issue we've seen in the past when the app isn't able to detect the new hardware.

Everything looks about right here, except that the GeForce 9400 is probably a lot higher than it should be compared to the other chipsets, despite the fact that we turned PhysX optimizations off to keep things on an even keel. Unfortunately, 3DMark can create an unrealistic expectation sometimes as we will see in the game benchmarks.

The PCMark results look to be where we would expect them, with the exception of a somewhat slower hard drive result for the 785G. We're looking into that but as of publication time we don't have a explanation. On the positive side, this phenomenon didn't seem to manifest itself in the rest of the benchmarks.

Let's run through SiSoft Sandra's gamut of synthetic benchmarks on all of these platforms, starting with the CPU arithmetic bench:

Not much variance here, but what is incredibly surprising is that these are the results of two different CPUs: the Phenom II X2 550, and the Core 2 Duo E7200. First glance would suggest these competitors are very evenly matched.

We're seeing the CPU's split up a little bit here, with the Phenom II X2 performing notably better when it comes to iSSE4.1

Here's where some real differences come into play. The Phenom II X2 and its integrated memory controller deliver significantly more memory bandwidth. Note that the GeForce 8200 board is running a little slower, as it's the only AMD system using DDR2 memory. Both of the Intel systems, also using DDR2, lose ground.

9. Benchmark Results: Audio And Video Encoding

Our audio encoding benches show the Intel-based systems are off to a good start. iTunes seems to really prefer the Core 2 Duo over the Phenom II. The Lame results are incredibly close, however.

The tables turn with DivX, Xvid, and H.264 encoding. The Phenom II X2 550 takes a strong lead over the Intel systems. Not surprisingly, the CPUs seem to have a notable effect on the results, while the chipsets and motherboards don't seem to make much difference. Within the AMD systems, the GeForce 8200 board trails a little due to its slower DDR2 memory.

10. Benchmark Results: 3D Rendering And Productivity

3ds Max doesn't show a huge difference between platforms or even CPUs. There is a slight advantage to the AMD systems, but not much.

The AVG scan seems to prefer high memory bandwidth over anything else. Note that the GeForce 8200 and its DDR2 are achieving a similar result compared to the Intel DDR2 systems.

While WinRAR seems to appreciate the Phenom II's memory speed, WinZip seems mostly oblivious to its bandwidth advantage.

11. Game Benchmarks: First-Person Shooters

Left 4 Dead is the new Starcraft when it comes to multiplayer fun, which should remain the case until Starcraft 2 comes out. Can these IGPs handle the game comfortably at medium settings?

At 1024x768, the 785G musters a very playable 34.9 frames per second (FPS), which is identical compared to the simulated 780G results and is very close to the 9400. The 790GX walks away with the win, but when we overclock the 785G to 800 MHz, it generates playable 1280x1024 performance. The G45 and GeForce 8200 boards are too slow to use.

With 2x anti-aliasing (AA) and 8x anisotropic filtering (AF) enabled, things slow down considerably for all parties, especially the Intel G45, which is not capable of AA here. The GeForce 9400, the 790GX, and the overclocked 785G are barely capable of playable performance at 1024x768.

Crysis is a demanding game, but the GeForce 9400, the 790GX, and the overclocked 785G squeak by with playable performance at 1280x1024. Unfortunately, they require turning graphics settings down to Low.

Increasing the shader detail to medium might look good, but it takes out almost all of the contenders. The overclocked 785G might be just fast enough to play with if you refuse to accept lower settings.

12. Game Benchmarks: Flight Sim And RTS

Even at the lowest details, Tom Clancy's H.A.W.X. is a gorgeous game. And judging from the frame rates, all of our contenders can handle 1024x768, while only the GeForce 8200 and Intel G45 are too slow for 1280x1024.

Trying the DirectX 10 version of the same game slows all of these platforms down. The G45 is knocked out entirely and the GeForce 8200 barely hangs in there at 1024x768.

Note that we benchmarked the 785G twice at stock speeds: once at DirectX 10 settings and once with the DirectX 10.1 option enabled. The DirectX 10.1 setting didn't result in increased performance, and in fact dropped FPS by a couple frames.

The 790GX and overclocked 785G excel in this game, even at 1280x1024.

Now for our real-time strategy (RTS) title, World in Conflict. At the low detail setting, all IGPs provide playable performance at 1024x768, although the GeForce 8200 and G45 are touch and go. At 1280x1024, these two contenders are knocked out, while the rest of the options remain playable.

Switching to medium details really slows things down to a crawl. The G45 couldn't run this setting without massive graphical corruption, so we had to give it a zero in this benchmark. None of the other contenders could muster playable FPS numbers.

13. HD Video Playback Benchmarks

Let's examine Blu-ray H.264 playback on a unique benchmark from the movie "Sunshine." The cool thing about this disc is that the picture-in-picture commentary only appears occasionally, so we can see the effect it makes on the first third of the data, while the remaining two-thirds display only a single video stream:

Indeed, it certainly looks like the new 785G chipset has no problem accelerating dual picture-in-picture video streams.

There are, of course, a lot more HD playback quality features to look at and test, but instead of concentrating on that here, we will research it extensively in our next Avivo HD, PureVideo HD, and Intel Clear Video comparative review in the very near future. Stay tuned.

14. GPGPU Benchmark

It's ATI Stream versus Nvidia's CUDA in this GPGPU-on-IGP shootout. We benchmarked the Cyberlink Espresso video converter, which is conveniently optimized to take advantage of both CUDA and ATI Stream and seems to be an ideal test.

Maybe not so ideal after all, as these results look somewhat strange.

We had a few odd occurrences of note during testing. First of all, when Espresso was run on the Nvidia 9300 chipset, the program gave us the option to turn hardware acceleration on or off, presumably to enable/disable the CUDA optimizations. The strange thing is that when optimizations were enabled, the video encoding took longer, which is the opposite of what we expected. We asked Nvidia about this phenomenon, and they claim that their testing shows even a 3 GHz Core 2 Duo E6850 should demonstrate a performance increase with CUDA enhancements enabled.

Nvidia also pointed out that these results are misleading unless the resulting encoded video is bit-for-bit identical, and they claim that their encoding is of a higher quality than the video resulting from the ATI Stream optimizations. They were also concerned that the version of Cyberlink Espresso AMD had provided was not a publically available build. We were actually working with both companies (and Cyberlink) on an image quality comparison, even before 785G showed up, so you can expect more detailed coverage there as soon as that project comes together.

15. Power Usage Benchmark

AMD has claimed great power savings with the 785G chipset and its Powerplay feature. Let's see how the platforms compare:

Now this test isn't an ideal way to compare the 785G to the 780G, as we only have a 790GX board on hand and underclocked it to simulate the 780G specifications for this test. However, the power draw difference is so slight between the 785G and simulated 780G that we doubt there'd be much of a difference with an actual 780G board.

Comparing platforms, it looks like the E7200 CPU on the Intel LGA 775-based boards uses less power than the Phenom II X2 550, which is no surprise, as the Phenom II X2 is a much faster CPU with a lot more cache. The Athlon II X2 250, however, sips even less load power than the Core 2 Duo E7200.

Analysis

Now, I'm all for environmental friendliness, but all too often I think the bottom line cost for an end-user is overlooked. So let's examine the power savings of the E7200 over the Phenom II X2 550.

At idle, the Phenom II X2 is drawing the highest load: 92 W on the 790GX motherboard. In contrast, the E7200 is drawing 66 W on the most efficient platform, Intel's G45. It looks big on the chart, but it's a difference of 26 W.

In the most populated coastal cities of the United States, electricity costs are the highest in the country at about 15 cents per kilowatt/hour. With this information, we can calculate the cost to use the Phenom II X2 550 compared to the Core 2 Duo E7200.

Let's compare the worst-case scenario, a PC with a Phenom II X2 550 and a 790GX motherboard, to the best-case scenario, a machine with a Core 2 Duo E7200 paired with a G45 motherboard. If you left a Phenom II X2 550/790GX-equipped PC in active idle state for 24 hours a day, you would be billed $34.16 more compared to the E7200/G45 in electricity costs every calendar year, and that's assuming you leave your computer on in an active state and don't turn it off or let it enter sleep mode.

This equates to big numbers for massive corporations deploying thousands of PCs, but for the home user it shouldn't be as much of a concern. In a home environment, I'd recommend the faster processor so that the performance is there when you need it. As for environmental concerns, Mother Earth is far better served by simply turning your PC off when it isn't being used.

There are two lessons to be learned here: first, if you really care about the environment, turn your PC off (or at least configure it to enter sleep mode) when you're not using it, and second, don't be afraid of purchasing a better processor for fear that it will cost you big money in power consumption.

16. Conclusion

Here's the bottom line: the 785G is a welcome update to a highly-regarded IGP, but with no more raw power than the 780G it will replace. The 785G is essentially the 780G chipset re-introduced with a number of attractive features, and it looks even better beside AMD's value-oriented Phenom II and Athlon II processors.

Is the 785G the best IGP out there? The answer is going to depend on what the PC will be used for and whether the apps you want to run work better with a Phenom II or Core 2 processor. With this in mind, let's examine a few of the primary reasons someone would want an integrated chipset, and specific recommendations for those applications.

Home Theater PC:


Which IGP is the best in a home theater PC? At this point I would have to say Nvidia's GeForce 9300/9400 and the 785G are running a close race, with the G45 slightly behind both due to a lack of picture-in-picture acceleration and a lower video playback quality (we'll explore this HTPC Blu-ray playback on these IGPs in a dedicated article in the very near future). Despite the update that 785G does not, in fact, feature eight-channel LPCM audio output, this remains a feature limited to a certain class of HTPC enthusiasts who run more complex speaker setups.

If money is a factor and eight-channel LPCM isn't necessary, then the 780G is the way to go at prices far below the GeForce 9300/9400.

Low-Cost Gaming PC:

For this specific use, I'd recommend skipping IGPs altogether and opting for a non-IGP motherboard of your choice in addition to a discrete graphics card. The Radeon HD 4350 is far more powerful than all of these IGPs, and can be found for under $35 online, while $50 gets you into Radeon HD 4650 territory and true 1280x1024 gaming. If you really don't have the $35 to spend, I'd recommend the 780G with a solid overclock to the graphics chipset. If you can't afford a discrete card today but plan on multiple cards in the future, the 790GX is the way to go with its dual-card CrossFireX capability.

All-Purpose PC

As a general, all-purpose PC for the home, I'd recommend the 780G or 785G, and not because of the chipset so much as the low cost of solid CPUs that drop into them. The Phenom II X2 and Phenom II X3 really do offer a great deal of performance for the price right now.

While Intel does offer its own low-priced Core 2 and Pentium dual-core gems, the G45 trades off too much in the graphics power department to be attractive, and the GeForce 9300/9400 motherboards are inexplicably expensive. The cheapest 780G motherboard is $45 less than the cheapest 9300 motherboard we can find, which is almost the cost of a discrete Radeon HD 4650.

In the final analysis, the 785G is a fine addition to AMD's chipset portfolio, and is perhaps most compelling for home-theater enthusiasts.