CrossFireX Arrives: First Look at 3 and 4 GPUs in 2 Card Setups
by Derek Wilson on March 7, 2008 12:05 PM EST- Posted in
- GPUs
S.T.A.L.K.E.R. Performance
Version: 1.0005
Settings: full dynamic lighting, everything maxed without AA and no grass shadows.
For this test, we walk in a straight line for about 30 seconds and use FRAPS to measure performance. We use the same save game every time and the path doesn't change. Our performance measurements are very consistent between runs. We do two runs and take the second.
S.T.A.L.K.E.R. is a strange one when it comes to performance. At some resolutions, quad-GPUs helps somewhat, but generally speaking the sweet spot is three GPUs. What's really perplexing is that we see quad help more at 1280x1024 than at 1600x1200 and 1920x1200. The performance benefits of three GPUs is also a bit erratic; though clearly at 2560x1600 the difference is noticeable, that resolution also demonstrates better scaling from two to three cards than from one to two cards - not something we would normally expect to see.
What we can say for certain is that the latest version of STALKER is not performing as well as we would expect in a variety of ways. It's not unusual to see multi-GPU technologies run into CPU limitations at lower resolutions and offer better scaling at higher resolutions, but that's not what we're seeing. Instead, we have our lowest and highest resolutions benefiting more from CrossFire (and CrossFireX) than our middle resolutions. We are looking into the matter more to see if we can determine what is actually happening; this could be something caused by the Skulltrail platform, the 1.0005 patch, the AMD drivers… or more likely than not all of these things working together.
CrossFireX has the potential to add value at all resolutions in S.T.A.L.K.E.R., but at present there are some anomalies (Ed: the kind they pay good money for around Chernobyl, we hear). Due to the nature of performance, gameplay and location in the game could make for huge variations in performance. Looking at the sky will push frame rate way up into the hundreds, so keeping more sky in your view than ground will improve your framerate. Thus, people who normally look higher while running around will experience better performance than those who look lower.
It's very hard with data like this to accurately assess the value of CrossFireX for this particular game. Based on the data we do have, it again seems that three GPUs is the sweet spot rather than four, in spite of the fact that four GPUs can help at both higher and lower resolutions.
| S.T.A.L.K.E.R. Performance | ||||
| 1280x1024 | 1600x1200 | 1920x1200 | 2560x1600 | |
| NVIDIA GeForce 9600 GT SLI | 94.3 | 72.8 | 62.6 | 39.9 |
| NVIDIA GeForce 8800 Ultra SLI | 110.3 | 94 | 85.2 | 61.6 |
| NVIDIA GeForce 8800 Ultra | 62.3 | 53.5 | 48.8 | 33.3 |
| NVIDIA GeForce 9600 GT | 51 | 38.7 | 33.3 | 21 |
| AMD Radeon HD 3870X2 (x 2) | 111 | 84.3 | 67.3 | 39.2 |
| AMD Radeon HD 3870X2 + 3870 | 103.5 | 83.4 | 68.2 | 36.9 |
| AMD Radeon HD 3870X2 | 86.3 | 68.5 | 59.6 | 24.1 |
| AMD Radeon HD 3870 | 43.7 | 34.3 | 29.5 | 17.5 |
Performance makes sense in general, but it is important to note the sharp relative drop of the 3870X2 at 2560x1600. This is a case where the 3870X2 doesn't appear to have the power to reach the next performance plateau, and adding in another graphics card really made the difference. That, or it's just another driver glitch that needs some ironing.
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MAIA - Tuesday, March 11, 2008 - link
"After rebooting a few times to let windows do its thing, we installed the driver and all was well."This sentence is soooooo microsoft windows !!! :))
Sorry .... had to say it.
dash2k8 - Tuesday, March 11, 2008 - link
I'm just wondering: instead of piling on the number of GPU's, why hasn't a manufacturer just come out with ONE monstrous GPU that does away with the need of using multiple video cards? If someone is crazy enough to spend moola on 4 GPU's, I imagine that person would be equally willing to buy ONE card that has the same horsepower. Just saying.punko - Monday, March 10, 2008 - link
Thanks Derek for a good review. As you indicated, this may be the future and its good to see the tech reach a point where it is ready for use and can be improved upon as all tech goes forward.It also sound like you had a lot of help directly from AMD on this one.
gsellis - Monday, March 10, 2008 - link
"but today a WHQL drier is available "Hey Derek, typo in the beginning. Still mirthful about this one. Water cooling and you needed it drier to work with all GPUs?
ltcommanderdata - Sunday, March 9, 2008 - link
I'm just curious as to whether you've checked to see if quad channel memory has any benefit for multiple GPU situations? With 3 or 4 GPUs sucking data, I would presume the additional memory bandwidth provided by quad DDR2-800 would increase performance, especially since dual channel FB-DIMMs are not as efficient as the best dual channel DDR2 or DDR3 setups on desktop boards. It would be interesting to see the results of a 4x1GB setup on Skulltrail vs the 2x2GB setup you used.cerwin13 - Saturday, March 8, 2008 - link
Would it be wise to try this upgrade without SP1 installed with Vista 32? I am currently using 2x Radeon HD3870 x2s and would like to benchmark with these new drivers, but apparently SP1 isn't officially out yet?DerekWilson - Saturday, March 8, 2008 - link
other people had luck without SP1; it's not a requirement, but some of our editors did find that it helped with a lot of stuff ...you'll want to make sure you have hotfixes:
929777-v2
936710
938194
938979
940105
945149
as a minimum
Ananke - Saturday, March 8, 2008 - link
XFX has Forceware 169.32, my guess it was added after 9600GT appear. On Nvidia official download site the highest ver is 169.28Ananke - Saturday, March 8, 2008 - link
XFX has Forceware 169.32, my guess it was added after 9600GT appear. On Nvidia official download site the highest ver is 169.28Incisal flyer - Saturday, March 8, 2008 - link
Derek, thanks for the very timely and detailed review. I'm going to be building a system for Flight Simulator X and have been trying to figure out the best graphics card(s) for that application. Have you considered benchmarking that sim? A lot of discussion right now on AVSIM etc on what to do in terms of GPUs for people building new systmes. There is a lot of back and forth on advantages and disadvantages of different configs. I realize FSX is a bit of a niche product. Would FSX use multiple GPUs like 2 3870 x2s and are the potential headaches of that configurtation worth it if you are a not a computer geek? Or am I better off just getting a couple of Nvidia 8800s in SLI or a single 3870 x2 and not hassling with the 4 GPU solution? Any help or advice would be appreciated. Thanks in advance for your time.Incisal Flyer