AMD's 785G Chipset - Revolutionary or Evolutionary?
by Gary Key on August 4, 2009 5:00 AM EST- Posted in
- Motherboards
Introduction
Remember when ATI made crappy chipsets that no one bought, and all AMD systems were built with NVIDIA or even VIA chipsets? Yeah, that memory is fading for us too.
Today we get to officially unveil the 785G, the latest in integrated graphics chipsets by AMD for AMD. As the name implies, there is very little separating 785G from its predecessor (780G) and we’re quite ok with that. In fact, the only reason not to get a 780G is addressed by the 785: the new chipset supports 8-channel LPCM audio over HDMI. The lack of TrueHD and DTS-HD audio bit-streaming remains but neither is this feature supported on other chipsets. We also see a jump from HDMI 1.2 to 1.3 standards. Update: This story is developing in real time but AMD is telling us that 8-channel LPCM over HDMI is not supported in the final chipset. More info here.
The rest of the major improvements are strictly related to video playback duties. We jump from Universal Video Decoder (UVD) 1.0 on the 780G to UVD 2.0 capabilities on the 785G. The video decode engine supports decoding multiple HD streams (useful for picture-in-picture on a Blu-ray movie) and additional post processing effects if you are not a big video purist. Also new is the 785G's ability to perform detail enhancements on the fly.
The graphics side has not really changed that much. The new GPU is based off the RV620 core and is roughly the same size/complexity as the old one. In other words we get the same 55nm node process and almost the same amount of transistors, just a tad over 205 million.The 785G’s PowerPlay technology is improved with the core constantly adjusting clock speeds based on GPU utilization with a 60MHz target when idling compared to 500MHz at full load. AMD adds DirectX 10.1 support but stream processor count and clock speeds have not changed. Thus gaming performance remains mostly unchanged.
And in this corner: Intel
AMD is targeting Intel’s G41 with this 785G, and by simply by adding 8-channel LPCM and UVD 2.0 support it is no longer at a feature deficit for the HTPC audience. In fact, we cannot find one area where the 785G comes up short compared to the G41.
Intel’s G41 is a cost-reduced version of Intel’s G45 chipset. You lose PCIe 2.0 support (1.1 only) and integrated Gigabit Ethernet (only 10/100). Considering Intel recommends mating the ICH7 Southbridge to the G41 for cost purposes, you also lose RAID support, four USB ports, and two 3GB/s SATA ports compared to the AMD SB710.
| AMD 790GX | AMD 785G | AMD 780G | Intel G45 | Intel G41 | NVIDIA GeForce 9300 | |
| CPU | AMD Socket-AM2 | AMD Socket-AM2 | AMD Socket-AM2 | Intel LGA-775 | Intel LGA-775 | Intel LGA-775 |
| Manufacturing Process | 55nm | 55nm | 55nm | 65nm | 65nm | 65nm |
| FSB | N/A | N/A | N/A | 800 / 1066 / 1333MHz | 800 / 1066 / 1333MHz | 800 / 1066 / 1333MHz |
| Memory Controller | N/A | N/A | N/A | 2 x 64-bit DDR2/DDR3 channels | 2 x 64-bit DDR2/DDR3 channels | 2 x 64-bit DDR2/DDR3 channels |
| Memory Speeds Supported | N/A | N/A | N/A | DDR2-800/667 DDR3-1066/800 |
DDR2-800/667 DDR3-1066/800 |
DDR2-800/667 DDR3-1066/800 |
| PCI Express | 22 PCIe 2.0 lanes | 22 PCIe 2.0 lanes | 22 PCIe 2.0 lanes | 16 PCIe 2.0 lanes | 16 PCIe 1.1 lanes | 20 PCIe 2.0 lanes |
| Graphics | Radeon HD 3300 | Radeon HD 4200 | Radeon HD 3200 | GMA X4500 | GMA 4500 | GeForce 9300 mGPU |
| Core Clock | 700MHz | 500MHz | 500MHz | 800MHz | 800MHz | 450MHz Core / 1.2GHz Shader |
| Shader Processors | 8 (5-way) | 8 (5-way) | 8 (5-way) | 10 | 10 | 16 |
| Full H.264/VC-1/MPEG-2 HW Decode | Yes | Yes | Yes | Yes | No | Yes |
The Radeon HD 4200 is where all the action is with this update but the more things change, the more they remain the same. We still have the traditional Northbridge/Southbridge layout with the NB supporting a 2GHz HyperTransport link compatible with the latest Socket AM3 processors. The 22 PCI Express 2.0 lanes are still around along with the four lane PCI Express 1.1 lanes supporting the A-Link Express connection between the two bridges.
The NB splits its 22 lanes between a single x16 link for graphics and six x1 links for expansion slots and onboard peripherals. Technically, the 785G chipset can't split its x16 graphics link into two x8 links for CrossFire X operation. The 785G supports hybrid CrossFire operation, but only with the older HD 3450/3470 video cards. We recommend skipping this feature, for now.
| AMD SB750 | AMD SB700 | Intel ICH10 | Intel ICH7 | NVIDIA GeForce 9300 | |
| Additional PCI Express | None | None | 6 x1 PCIe 1.1 | 4 x1 PCIe 1.1 | None |
| USB | 12 ports | 12 ports | 12 ports | 8 ports | 12 ports |
| SATA (300MB/s) | 6 ports | 6 ports | 6 ports | 4 ports | 6 ports |
| PATA | 2 channels | 2 channels | None | None | 1 channel |
| RAID* | RAID 0/1/5/10 | RAID 0/1/10 | RAID 0/1/5/10 | None | RAID 0/1/5/10 |
| HD Audio Interface | Yes | Yes | Yes | Yes | Yes |
| Ethernet | Not Integrated | Not Integrated | Intel Gigabit LAN | Intel 10/100 LAN (Gigabit through external controller) | NVIDIA Gigabit LAN |
| Northbridge Interface | 4 lane PCIe 1.1 | 4 lane PCIe 1.1 | DMI 10Gb/s each direction, full duplex | DMI 10Gb/s each direction, full duplex | N/A, Single Chip Solution |
The SB710 is essentially an updated SB700 with ACC (Advanced Clock Calibration) support, or looking at it a different way, a cost reduced SB750 without support for RAID 5 arrays. The SB710 has six 300MB/s Serial ATA ports with RAID 0, 1, and 0+1 support plus a single IDE port supporting two drives so JMicron and Marvell are held at bay on these systems. Twelve USB ports and a high-definition audio interface round out the SB710 as native GbE support is still missing.
It would have been nice to see next-gen USB and SATA support but that will have to wait for the SB8xxx updates next year. However, compared to the ICH7 mated with the G41, the SB710 is positively feature rich at the same price point.
We could continue on with subtle hints about why this chipset is a better alternative than the Intel G41 or its 780G/790GX siblings, but the bottom line is that AMD has taken an evolutionary step with this chipset, one for the better. That said, let's see how it performs against the other chipsets in its class.
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43 Comments
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Hrel - Saturday, August 22, 2009 - link
You showed Nvidia stats on the first page... I guess you didn't include them cause ATI and Intel can't even compare???Next time include the Nvidia results... would've thought that it'd an impulsory action; guess not.
crochat - Tuesday, August 18, 2009 - link
Gary,You mentioned a motherboard roundup in your conclusion. I thought it would come sooner.
Regards
AlB80 - Sunday, August 16, 2009 - link
1. The A-Link Express II is a proprietary interface developed by AMD basing on the PCI Express Gen2 version 2.0 technology, with additional Northbridge-Southbridge messaging functionalities.2. High data transfer bandwidth (up to 2.5 Gb/s / Lane)
Concillian - Saturday, August 15, 2009 - link
"Remember when ATI made crappy chipsets that no one bought, and all AMD systems were built with NVIDIA or even VIA chipsets? "Yeah, I remember that, thats when they were really AMD chipsets and not ATi chipsets with an AMD label on them. ATi started making good Crossfire chipsets shortly before AMD bought them.
I like AMD as much as the next guy, but let's not be patting them on the back too hard. They tried, failed, then did what any good American businessman would do... bought a struggling competitor to use their IP.
IntelUser2000 - Saturday, August 8, 2009 - link
Gary, you got the clock speed of the G41 IGP wrong:http://www.techarp.com/showarticle.aspx?artno=543&...">http://www.techarp.com/showarticle.aspx?artno=543&...
G41 and G43 uses a 667MHz core while G45 uses 800MHz.
Notice the differences here: http://global.hkepc.com/1525/page/3#view">http://global.hkepc.com/1525/page/3#view
ClagMaster - Saturday, August 8, 2009 - link
The 785G is just a 780G which has recieved a fine tuning. Which is OK. There are slight improvements in performance over the 780G but nothing to be excited about. 785G Seems to work well with DDR3 memory and Athlon II processors.I have an ASUS M3A78EM 780G Mobo with an AMD BE2400 X2 CPU I use as a secondary computer I keep off-line for private matters. It's a fairly powerful rig for the media applications I run.
The HD 3200 GPU is just as powerful as a Geforce 4200 graphics card. I can play DX8 and DX9 games from the 2002-2004 period (Max Payne, Aquanox, Homeworld2) with acceptable framerates at 1280 x 1024 resolution. I run Windows XP Home.
The 785G is not bad. But if I had a choice between a 785G mobo and a 780G mobo with the 780G costing $5-$10 less, I would buy the 780G mobo. I can still run Windows 7 with the 780G with the HD3200.
ClagMaster - Saturday, August 8, 2009 - link
BTW-This article was not boring. It honestly compared the performance capabilities of the 785G to other chipsets of its class (780G and G41).
Most differences between the 785G and 780G were small and within the combined statistical uncertainty of the benchmark measurements measurements +/-10% (i.e. statistically insignificant). Not very surprising. Most of the larger differences observed were between systems with DDR2-1066 and DDR3-1333 memory systems.
I agree the 785G is a better balanced chipset than the 780G and G41 for multimedia.
I wish Gary would have used an older benchmarking suite so I can compare the performance between current and systems 2-3 years old. I prefer PCMark2005 and 3DMark2005 since these are reliable indicators of performance. This is important to me because I try to make my purchasing decisions on the criteria of having double the performance for the same cost and power consumption.
ClagMaster - Saturday, August 8, 2009 - link
BTW-This article was not boring. It honestly compared the performance capabilities of the 785G to other chipsets of its class (780G and G41).
Most differences between the 785G and 780G were small and within the combined statistical uncertainty of the benchmark measurements measurements +/-10% (i.e. statistically insignificant). Not very surprising. Most of the larger differences observed were between systems with DDR2-1066 and DDR3-1333 memory systems.
I agree the 785G is a better balanced chipset than the 780G and G41 for multimedia.
I wish Gary would have used an older benchmarking suite so I can compare the performance between current and systems 2-3 years old. I prefer PCMark2005 and 3DMark2005 since these are reliable indicators of performance. This is important to me because I try to make my purchasing decisions on the criteria of having double the performance for the same cost and power consumption.
7Enigma - Thursday, August 6, 2009 - link
Gary,Thanks for the article but could you keep in mind for future articles on non-gaming hardware (i.e. IG's, budget GPU's, etc.) to make sure the game description is in line with the actual article? I can tell they were just copied directly from a previous gaming article, so it's a bit silly to see, "We crank up all the details to max", only to see the data chart show 1024X768 with low settings.
:)
AlB80 - Wednesday, August 5, 2009 - link
DMI 10Gb/s each direction, full duplexaka
4 lane PCIe 1.1