SLI vs. CrossFire, Part 1 – mid-range multi-GPU scaling & value
Call Of Duty 4: Modern Warfare
Call of Duty 4: Modern Warfare (CoD4) is a first person shooter running on a custom engine. It has nice graphics but the engine is somewhat dated compared to others and it runs well on modern PCs. It is the first CoD installment to take place in a modern setting instead of in World War II. It differs from the previous Call of Duty games by having a more film-like plot that uses intermixed story lines from two perspectives; that of a USMC sergeant and a British SAS sergeant. There is also a variety of short missions where players control other characters in flashback sequences to advance the story. Call of Duty 4’s move to modern warfare introduced a variety of modern conventional weapons and technologies including plastic explosives.
There are currently about 20 multiplayer maps in CoD4. It is very popular and there is a new expansion for it. CoD Modern Warfare 2 was also released with updated visuals but it is also not very demanding on graphics cards. For multiplayer, CoD4 includes five preset classes and introduces the Perks system. Perks are special abilities which allow users to further customize their character to suit their personal style.
Our timedemo benchmark was created by ABT’s own Senior Editor and lead reviewer, BFG10K. It is very accurate and totally repeatable.
Here is CoD4, first at 2560×1600 resolution with all in-game settings completely maxed out plus 4xAA:
We see some pretty good scaling that approaches 100% in some cases. Scaling greater than 100% can be attributed to benchmark “noise”, the way averages are rounded off. or the nature of Alternate Frame Rendering (AFR) and we will expand on this in our conclusion. Here we see the HD 5870 – although not the strongest single-GPU performer – leads when it is in CrossFire. However, even GTX 460 SLI is enough to beat the GTX 580. Let’s next test at 1920×1200.
We see that a popular multiplayer game is very playable even on midrange graphics cards and it plays very smoothly with this generation’s top video cards. We also see GTS 450 SLI even hang with the GTX 480 and the GTX 570.
I’m not 100% certain, but to analyze microstuttering, place a check in the box next to “Frametimes” in Fraps. Then when you press the hotkey, it will create a log file with a timestamp when each single frame was outputted. Only a few seconds is enough to make the log file really, really long. Then take a portion out of the log file and make a chart out of it, that measures the time between each timestamp, to see if the frames are consistent with each other in similar intervals, or if every other frame is too close to the other one.
If a game runs at say, 45fps with your SLI or CF setup, but feels more like 23-30fps, then definitely analyze this with FRAPS.
Great review so far.
How do the numbers change, if at all, if Split Frame Rendering is used instead of Alternate Frame Rendering?
The last time I used SLI was with my Voodoo2 3000s. It was a gigantic waste of $200, in 1996 dollars.
If SFR eliminates micro-stutter without too much of a performance penalty I might have to try SLI again.
why don’t they add BF:BC2?
and also 6950 n 6970 crossfire?
Concerning the microstutter, frames time (using that fraps option) is supposed to fluctuate more erratically on crossfire/sli than what it would be on a single card. I think instead of testing a moving scene, it would make more sense to test it on a completely still scene for a few seconds and see how they compare in the excel output file. You don’t want a moving scene because then you won’t be able to differentiate between the erracticness you would get from a moving scene and the erraticness you would get from microstutter.
Another interest option would be to downclock a sli/crossfire setup to a point where it matches the average framerate of the single card. This way you could could see if the multi-gpu setup looks choppier than a single card despite having the same average frame rate.
Excellent work! At the end, simple recommendations would have been nice. =)
Please include Civilization 5 if possible the next time you benchmark.
It is an important game which will test the tesselation feature and its scaling ability in multi-gpu configurations.
Civilization 5 has been added to my benching suite along with DiRT 3 and Total War, Shogun 2.
You’ve done a great job of benchmarking gaming performance, but including charts with FPS vs $$, and $$ vs wattage would be much more useful.
The wattage (both idle and load) figures can be especially important, as some of these cards can easily draw more juice than all but the most powerful (and expensive) power supplies can provide — and that definitely factors into the cost analysis.