ATI Radeon HD 4850 Preview: AMD Delivers Performance for the Masses
by Anand Lal Shimpi & Derek Wilson on June 19, 2008 5:00 PM EST- Posted in
- GPUs
Challenging NVIDIA's Strategy: Are Two RV770s Faster than One GT200?
NVIDIA insists on building these massive GPUs while AMD is heading in the direction of multiple, smaller GPUs in order to keep development time and costs manageable. Does NVIDIA's strategy make sense? In order to find out we paired two Radeon HD 4850s in CrossFireX and ran through our benchmark suite, this time focusing on a comparison to the recently announced GeForce GTX 280 as well as the 9800 GX2. The results were surprising:
| AMD Radeon HD 4850 CF | NVIDIA GeForce GTX 280 | NVIDIA GeForce 9800 GX2 | 512 256MB|
| Crysis | 36.4 | 34.3 | 39.9 |
| Call of Duty 4 | 88.2 | 67.4 | 73.2 |
| Enemy Territory: Quake Wars | 53.7 | 70.2 | 62.2 |
| Assassin's Creed | 51.9 | 45 | 52.6 |
| Oblivion | 39.5 | 36.8 | 35.6 |
| The Witcher | 20.9 | 37.7 | 37.6 |
| Bioshock | 68.6 | 63.9 | 75.4 |
So does AMD's approach invalidate NVIDIA's big-monolithic-GPU strategy? Not exactly. While it is true that two RV770s can outperform a single GT200 in many cases, you could also make the argument that two GT200s could outperform anything that AMD could possibly concoct (3 and 4-way CF scaling isn't nearly as good as 2-way). AMD's strategy makes sense, for AMD, but it's fundamentally no different than what NVIDIA is doing - AMD is simply targeting a different initial market and scaling up/down from there.
The scaling, or lack thereof, in games like Enemy Territory: Quake Wars highlights an important caveat with AMD's strategy: there are still software issues with SLI and CrossFireX. What is necessary is a truly seamless multi-GPU implementation, with shared frame buffer and where both GPUs operate as an extension of each other with direct GPU-to-GPU communication over a high speed (not PCIe) bus, similar to how AMD's Opteron or Intel's Nehalem work in multi-socketed systems.
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docmilo - Thursday, June 19, 2008 - link
I browsed on over to the Egg and did a search on 4850. A whole bunch of cards popped up at $199.99 and one even has a rebate! I wonder how long until it stops saying "Buy Now" and goes to "Autonotify".chizow - Thursday, June 19, 2008 - link
You guys did a nice job of covering both the pros and cons of the 4850 and CF, showing some of the pitfalls of relying on multi-GPU solutions for performance. You also made mention that similar performance gains were seen long ago with the 8800GT.That said the 4850 is certainly a good part from AMD and there's definitely some very interesting things they've done with this card. You hinted at a lot of them with the architectural changes but there's a few other sites that hinted at some of the changes. Its clear ATI has drastically improved their memory controllers and cache design along with their render back ends for AA performance.
I think the real thing to keep an eye on though is how AMD managed to get near 100% scaling with CF. Extremetech hinted at improved memory controllers and a gpu communications "Hub" here http://www.extremetech.com/article2/0,2845,2320865...">http://www.extremetech.com/article2/0,2845,2320865... for improved performance between GPUs. I'm sure you guys will cover these improvements in detail in your complete review, but it looks like that hyper transport mechanism you alluded to.
MadBoris - Thursday, June 19, 2008 - link
Nice to see AMD staying competitive, plus keeping prices down.I think the days of me spending $400+ on a video card are behind me, atleast for the foreseeable future. You have to provide alot more than 10% performance increases for an extra $250 NVIDIA.
I'm rather surprised NVIDIA has not really capitalized on taking a huge performance lead and crown with all the AMD post merger dust settling.
I'm pleasantly surprised that AMD is continuing to excel with HW. If only they would bring back an AIW card, I'd buy one, but my current 8800GTS is not so outmatched that it is worth upgrading to anything this generation.
Good article Anand.
fungmak - Thursday, June 19, 2008 - link
Looking at the CF perfomance of other sites who used cat 8.6, IIRC were a lot better than the current AT results.Just wondering if there is an intention to update using cat 8.6?
derek85 - Friday, June 20, 2008 - link
I second this, I'm sure 8.6 came with some nice optimizations on 770s.DerekWilson - Friday, June 20, 2008 - link
we did not use catalyst 8.5 drivers.we used the very latest beta drivers ATI could get us.
Wirmish - Friday, June 20, 2008 - link
And did you use the Radeon HD 4800 Series Hotfix (6/20/2008) ?http://support.ati.com/ics/support/default.asp?dep...">http://support.ati.com/ics/support/default.asp?dep...
;)
Nighteye2 - Thursday, June 19, 2008 - link
The big question for the comparison between this card in CF and the GT200 will not be the classic framerates here - but the performance of games that use the GPU for part of the physics processing. The GT200 has lots of compute power to spare for physics, can 2 4850's in CF match that?FITCamaro - Friday, June 20, 2008 - link
With 800 shaders it wouldn't surprise me.Wirmish - Friday, June 20, 2008 - link
He talk about CF...So it's 1600 shaders !