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AMD 780G Overclocking and Performance Preview March 12, 2008 Brandon Sandman Bell |
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Summary: With its 55-nm manufacturing process, we had high hopes for OC'ing AMD's 780G chipset. It certainly didn't disappoint! In this article we go over the highlights and performance of the new chipset -- you may be pretty surprised by the results we saw from a $100 motherboard...
 AMD 780G Performance and Overclocking Preview | Page:: ( 1 / 14 ) |
At the heart of the 690G was ATI’s Radeon X1250 integrated graphics processor. Largely derived from ATI’s Radeon X700 family on the desktop, the X1250 IGP featured a 4-pixel shader architecture, with four texture units and a 400MHz clock speed. The GPU lacked vertex shaders, offloading that functionality to the CPU instead, but this was typical of all chipsets of that era. Where it stood out was its versatility as a platform: its IGP performance was excellent, as well as its display flexibility, and it was priced to move.
Then Intel released their next-generation, Bearlake-G, G35 chipset. On paper, G35 had a couple of features going for it that weren’t offered by AMD-690.
Most notable was DirectX 10 support. Its GMA X3500 graphics core was the first to offer full support for Microsoft’s latest API. While any hardcore gamer knows that DX10’s adoption rate has been slow at best to date due to its performance (turning on DX10 features in many games drastically saps performance) and lack of a real killer game release, to a system builder or OEM, this is a really important check mark feature that G35 boasts over AMD-690. The G35 chipset also offers hardware-based vertex shaders.
The 780G chipset is AMD’s answer to G35. The chipset is built around a brand new IGP supporting DirectX 10 graphics functionality, PCIe 2.0, HyperTransport 3, and one interesting new feature known as Hybrid Graphics. With Hybrid Graphics you can combine the integrated graphics found in the 780G chipset with a Radeon HD 3450 or 3470 discrete graphics card for more performance. Think of it like CrossFire, but for chipsets. We took a look at Hybrid Graphics performance last week and found the IGP+3450 combination was capable of delivering a performance improvement of 2X in certain cases (Company of Heroes performance more than doubled actually)!
780G is also based on TSMC’s smaller 55-nm process, allowing it to consume less power than 690G despite its increased functionality. AMD claims idle power consumption of the IGP is just 0.95W! The 780G chipset also consists of a new SB700 South Bridge. This new chip is mainly an evolutionary upgrade over AMD’s previous SB600 South Bridge, integrating a revamped USB controller with support for two additional USB 2.0 ports.
Let’s go over the new chipset in more detail…
| Inside the 780G chipset | Page:: ( 2 / 14 ) |
The 780 chipset contains 205 million transistors, that’s over twice the number of transistors in 690G, which contained just 72 million. The majority of these new transistors go towards adding DX10 functionality to chipset’s IGP, dubbed the Radeon HD 3200.
The Radeon HD 3200 IGP is largely based on AMD’s RV620 GPU, which was originally launched in the Radeon HD 3450/3470 back in January. If you recall, RV620 is essentially the die shrunk equivalent of RV610, which debuted in the Radeon HD 2400 family nearly a year ago.
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The Radeon HD 3200 IGP features the same unified shading architecture found in the 2400 and 3400 series of GPUs, with 40 stream processors and a 500MHz core clock speed. At 500MHz the 3200 IGP is a little slower than RV610, which ran as slow as 525MHz on the Radeon 2400 Pro, and 700MHz for the 2400 XT (in comparison, the 3450 runs at 600MHz and the 3470 at 800MHz), but some motherboard manufacturers will be offering the ability to overclock the 3200 IGP from within BIOS, allowing end users to make up the difference a little. AMD also says that their motherboard partners are free to integrate their own dedicated frame buffer memory for graphics onto the motherboard, but in the past this feature has rarely been found on other integrated motherboards due to increased costs. Instead system memory is used. The 3200 IGP can address up to 512MB of system RAM.
By essentially taking RV620 and dropping it into an IGP, AMD is able to add support for their Hybrid Graphics technology. Simply pair a discrete RV620 graphics card up to your existing 780G system for a nice boost in 3D gaming performance. Like CrossFire, Hybrid Graphics is only as fast as the slowest component, so you’ll want to pair the IGP up to a similarly clocked and configured graphics card for the most bang for your buck. In other words, while you can pair the IGP up to a 3870, the graphics core will be limited to 500MHz (unless of course you’re willing to OC the IGP). Likewise it would probably be a good idea to pick up a card with 512MB of memory.
As we mentioned on the previous page, 780G supports 1.8GHz HyperTransport 3 when paired with a Phenom processor. The motherboard reverts to 1.0GHz HyperTransport when an Athlon 64 CPU is used. The added bandwidth provided by HT 3 is needed in order to enable high definition post processing, but the other Radeon 3450 Avivo video features are fully supported regardless of the CPU used.
PCI Express 2.0 is also supported. The chipset has 26 PCIe 2.0 lanes total, 16 for the graphics slot and six lanes for the PCIe expansion slots. The remaining four lanes connect the North Bridge to the South Bridge.
Speaking of the South Bridge, the new SB700 South Bridge is largely similar to its predecessor, SB600. AMD has integrated a new dual-channel USB controller to improve transfer rates and have also increased the number of supported USB 2.0 devices from 10 ports to 12. AMD also adds support for 2 USB 1.1 ports in addition to the USB 2.0 ports. The number of SATA drives supported has also been increased from four in SB600 to six in SB700. The SATA controller supports SATA 2 drives with NCQ as well as RAID Levels 0, 1, and 10. One parallel ATA controller is also provided (supporting up to two drives) for older drives.
Other than these changes, SB700 is basically the same as SB600 from a pure features perspective.
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AMD-780V
Sitting below the 780G at the bottom end of the 780 family, AMD will also be producing their 780V chipset. 780V runs at 400MHz and lacks support for SurroundView, DisplayPort, Hybrid Graphics, and UVD. AMD is targeting 780V for business/office use, where these features are obviously counterproductive to office productivity. 780V is basically intended for IT managers looking for an affordable alternative to Intel.
For these types of users, the 780V platform should be particularly intriguing once triple-core debuts. The argument from AMD will likely be that you can get a low-cost triple-core platform from AMD at a price similar to Intel’s dual-core.
| The ASUS M3A78-EMH HDMI | Page:: ( 3 / 14 ) |
To test the prowess of AMD’s new chipset, we’ve received two motherboards, the ASUS M3A78-EMH HDMI and the Gigabyte GA-MA78GM-S2H.
Both motherboards offer a nice array of display connectivity options, with VGA, DVI, and HDMI outputs all available on the backplane of the motherboard. The Gigabyte motherboard even ships with a S/PDIF audio output on the back plane as well. The ASUS board is currently selling for $90 on Newegg, while the GA-MA78GM-S2H sells for $100. We’ll start with the ASUS M3A78-EMH HDMI first.
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ASUS M3A78-EMH HDMI
So far ASUS has announced three 780G motherboards, the M3A78-EH, the M3A-H/HDMI, and the M3A78-EMH HDMI. The M3A78-EMH HDMI is ASUS’ micro-ATX motherboard, while the other two boards are full-sized ATX boards.
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The M3A78-EMH HDMI may be small in stature, but ASUS has outfitted the board with a nice array of features. As we mentioned above, display options include DVI, VGA, and HDMI, giving end users lots of flexibility when it comes to display outputs. One feature we were a little disappointed to see omitted from the boards we’re testing today is dual-link DVI, but if you can afford a 30” panel chances are you aren’t going to run it on an integrated graphics solution.
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For expansion, ASUS outfits the M3A78-EMH HDMI with one PCI Express graphics slot, two PCI slots, and a single x1 PCIe slot. The motherboard supports ASUS’CPU Parameter Recall (CPR) technology, which will automatically load the BIOS in safe mode after an unsuccessful overclock. The board also supports ASUS CrashFree BIOS which allows you to restore corrupted BIOS as well as their Q-Fan technology which can be used to dynamically adjust fan speeds.
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The BIOS interface
Unfortunately, the M3A78-EMH HDMI BIOS doesn’t support IGP overclocking. Despite the massive aluminum heatsink ASUS provides on the board, ASUS apparently doesn’t want you to dabble with IGP OC’ing. As you’ll see in our OC’ing results further down the page, this could be a major oversight in the current BIOS on ASUS’ part.
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The rest of the board’s BIOS isn’t much better for overclockers. For instance, while ASUS does provide HyperTransport speeds for OC’ing the CPU, there aren’t any options in BIOS for adjusting voltages. Not even DRAM voltages could be adjusted in the 0043 BIOS we used for testing! This is a little concerning, as some enthusiast-oriented DDR2 modules need higher voltages to run successfully, but we didn’t run into any issues with the Corsair, Kingston, or OCZ modules we had available for testing.
Our guess is that ASUS assumes someone who buys a $90 motherboard isn’t going to pay extra for a higher-end memory module, and in all honesty this assumption is probably correct, but we still think a couple of voltage options for system RAM would be a good idea.
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ASUS does provide HyperTransport speeds ranging from 200-300MHz in 1MHz increments. They also continue to provide their OC Profile settings which will automatically OC your CPU by 2, 5, 8, or up to 10% over the default clock speed (this is useful for newbies who may not want to fiddle with BIOS settings when OC’ing), but if you’re an enthusiast who wants to tweak every ounce of performance out of your CPU, and ultimately your entire system, the BIOS ASUS currently provides in the M3A78-EMH HDMI isn’t for you. It just isn’t built for OC’ers. This probably wouldn’t be such a bad thing, after all, considering the target market of the 780G chipset, its unlikely that many of these users will want to overclock an integrated platform, but after seeing the OC’ing results we got from the Gigabyte motherboard, we can’t help but wondering the full potential of the M3A78-EMH HDMI. Click over to the next page to see why we say this…
| Gigabyte GA-MA78GM-S2H | Page:: ( 4 / 14 ) |
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Gigabyte’s GA-MA78GM-S2H sells for a premium in comparison to the ASUS motherboard, so you’re probably wondering what that extra $10 buys you. Well, both motherboards sport PCIe-based Gigabit Ethernet controllers. Both motherboards rely on Realtek’s 8111C chip for networking duties. Gigabyte however, uses Realtek’s newer ALC889A codec for audio.
The 889A chip supports DTS Connect and boasts a 106dB signal-to-noise ratio. The ALC883 codec used on the ASUS motherboard is Realtek’s value 8-channel offering.
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Gigabyte also uses a more robust 4-phase power delivery system with all-solid capacitors for the CPU’s VRM circuitry. In theory, this should give the Gigabyte board an edge when it comes to overclocking.
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Gigabyte also provides more connectivity options on the backplane of their motherboard. In addition to the display outputs, you’ll find a FireWire, eSATA, and S/PDIF connections on the back panel of the Gigabyte motherboard. ASUS elected not to include these features on the back of the M3A78-EMH HDMI.
BIOS
Inside BIOS, Gigabyte provides IGP clock settings ranging from 150-1100MHz in 1MHz increments and HT speeds ranging from 200-500MHz in 1MHz increments.
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You can also adjust PCIe speeds up to 200MHz, tweak the clock multiplier, and the memory speed.
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When it comes to voltages, Gigabyte limits you to 2.15V max on the memory while the North Bridge can be overvolted up to 0.3V over default. CPU voltages up to 1.9V are available in increments of 0.25V, although at the upper end of the spectrum (above 1.6V) the increments increase to 0.50V.
Overclocking
With its 4-phase power circuitry, we focused our overclocking efforts on Gigabyte’s GA-MA78GM-S2H motherboard exclusively. We were eager to see how far we could push the $100 board, and we certainly weren’t disappointed!
We started by OC’ing just the IGP. AMD representatives told us that they’d built the platform with headroom for OC’ing during our 780G briefing so we were eager to see how far the chip could go. We decided to go for broke, jumping in 100MHz increments. 600MHz passed with flying colors, then 700MHz. We were pretty nervous at 800MHz, but the IGP ran all of our benchmarks without breaking a sweat.
We cringed at the thought of dialing in 900MHz, so we next shot for 850MHz. Pass. 900MHz? Not so lucky. While Company of Heroes, F.E.A.R., and Episode Two ran without a hitch, we weren’t able to get Crysis to run with complete stability. We repeatedly got blue screens after just a few minutes of testing. Next we shot for 875MHz. At that speed Crysis held up a little bit longer, but it still wasn’t completely stable. Ultimately we had to settle on a speed of 855MHz to get the game to run 100%.
Keep in mind that we were able to hit this speed relying entirely on the passive cooling provided by Gigabyte. We didn’t add any additional cooling to the system, not even a nearby system fan. The only fan within the system was the fan provided by the CPU cooler.
Running at this speed without any cooling, the IGP got quite toasty – hot enough to burn your finger if you touched the IGP for more than a fraction of a second – but the system ran completely stable despite this. Obviously in a real world scenario where the system isn’t on a testbed being pushed to the max we would have placed a fan on or near the North Bridge of the chipset to provide additional cooling.
In any case, a 355MHz overclock of the IGP is nothing to scoff at.
With the max OC of the IGP determined, we next set out to see how far we could push the combined Athlon 64 X2 4850e/GA-MA78GM-S2H platform with the IGP still OC’ed at 855MHz. Ultimately we settled on a speed of just over 3GHz at 1.375V of juice:
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Not bad for a $100 motherboard and $90 CPU!!!
| System Setup | Page:: ( 5 / 14 ) |
Intel Core 2 Duo E4500
ASUS P5E-VM HDMI
AMD Athlon 64 X2 4850e
ASUS M3A78-EMH HDMI
Gigabyte GA-MA78GM-S2H
2GB Corsair TWIN2X2048-6400C4
150GB Western Digital Raptor
Windows Vista Ultimate 64-bit w/Service Pack 1
Benchmarks
Company of Heroes 1.71 (running DX9)
F.E.A.R. 1.08
Half-Life 2 Episode Two
Lost Planet DX9
Crysis
| Media Benchmarks | Page:: ( 6 / 14 ) |
| Storage Benchmarks | Page:: ( 7 / 14 ) |
HDTach SATA Performance
HDTach USB Performance
| F.E.A.R. Performance | Page:: ( 8 / 14 ) |
F.E.A.R. – Direct3D
| Company Of Heroes DX9 | Page:: ( 9 / 14 ) |
Company of Heroes – Direct3D
| HL2 Episode 2 | Page:: ( 10 / 14 ) |
Episode Two – Direct3D
| Lost Planet | Page:: ( 11 / 14 ) |
Lost Planet – Direct3D
| Crysis | Page:: ( 12 / 14 ) |
Crysis – Direct3D
| Power and Overclocking | Page:: ( 13 / 14 ) |
| Conclusion | Page:: ( 14 / 14 ) |
Technically, AMD isn’t first to deliver a DX10 IGP, but as we just saw the gaming performance of Intel’s GMA X3500 graphics core is so anemic it’s practically useless if you want to play a game based on a modern DX9 game engine. DX10 is a definite no-no. The Radeon HD 3200 IGP isn’t powerful enough to replace a modern $100-$200 discrete graphics card, but for an IGP that comes standard with your motherboard, it’s impossible not to be impressed by what AMD has delivered with the 3200 IGP.
What really sweetens the package is Hybrid Graphics. Say you’re a casual gamer who’s content to play poker online and every once in awhile you’ll hop on a server to play an old classic like Counter-Strike 1.6. For this type of gamer, the 3200 IGP is more than sufficient by itself. But say your son (or daughter) wants to play a more modern game like Episode Two or Company of Heroes. Rather than plopping down the big bucks for a new mainstream or high-end GPU, a $50 Radeon HD 3450 can buy you a boost of 2x or more in some cases over the IGP alone. If you’ve got a good 780G motherboard, you can even OC the IGP and graphics card for even more performance. Just check out our Gigabyte OC’ing results on the previous page!
You can’t do this with Intel’s integrated platform. And at the moment, you can’t do it with NVIDIA’s either. For right now, this feature is exclusive to AMD, and it really drives home the whole platform message AMD has been preaching for the last year and a half. Simply take an AMD-based CPU and motherboard, and pair it with an appropriate AMD-based GPU for more performance. This could potentially drive 3450 sales if AMD and system vendors market Hybrid Graphics appropriately: inside the packaging of every 780G PC and motherboard AMD needs to include promotional material marketing Hybrid Graphics.
HTPC users will appreciate the 780G’s low power consumption, as well as its high definition playback prowess. We noted significantly lower CPU utilization scores for 780G in comparison to Intel’s G35 chipset with AVC content, VC-1 was much closer but still the edge went to AMD. Our audio/video encoding and rendering tests favored the Intel platform, but these are CPU-oriented tests that have always favored the Core 2 architecture over AMD’s older Athlon 64 X2 architecture. The Core 2 Duo E4500 CPU we used for testing is also more expensive than the X2 4850e we used for the 780G platforms.
The only real chink in 780G’s armor is its SATA controller. Our storage tests favored Intel’s G35 platform. This is because we ran into numerous issues trying to run the 780G platform with AHCI enabled and ultimately couldn’t get it to run successfully. This is an issue that also plagued the 690 platform and desperately needs to be addressed by AMD. Fortunately this isn’t an issue that completely cripples performance, but it is disappointing nonetheless.
When it comes to 780G motherboards, with its more robust BIOS and feature set, we’re giving the early edge to Gigabyte’s GA-MA78GM-S2H for right now. This motherboard currently sells for a little more than the ASUS motherboard, but as we outlined earlier, the Gigabyte board is worth the extra dough. Hopefully ASUS will consider beefing up the M3A78-EMH HDMI’s BIOS, as it just isn’t powerful enough to suit the needs of enthusiasts as it stands right now.
NVIDIA is putting the finishing touches on their GeForce 8200 IGP. The 8200 supports NVIDIA’s Hybrid SLI technology, DirectX 10, and PureVideo HD. We’ll be curious to see how the GeForce 8200 stacks up against AMD’s 780G, but for right now AMD’s got the best integrated platform on the market at the moment.