SLI vs. CrossFire, Part 1 – mid-range multi-GPU scaling & value
Mafia II
Mafia II is a third-person action-adventure video game which is the sequel to Mafia: The City of Lost Heaven. It is developed by 2K Czech and is published by 2K Games and was released last year. Mafia II is set from 1943 to 1951 in Empire Bay which is a fictional city based mostly on San Francisco and New York City along with some influences from Chicago and also Detroit. Mafia II is a gritty drama which chronicles the rise of World War II veteran Vito Scaletta who joins the Falcone Crime Family and becomes a ‘made’ man. There are 15 chapters in the game and over two hours of game engine generated cutscenes.
Mafia II makes extensive use of Nvidia’s PhysX whose full effects are seen smoothly only by playing on a PhysX-enabled GeForce and preferably with a second video card dedicated to it. For this article, we used the full retail game with Mafia II’s built-in benchmark with the highest settings for 2560×1600 and 1920×1200 – without PhysX – and this time we will reserve comment until after both charts. First we test at 2560×1600.
Now at 1920×1200:
The GTX 580 is the fastest followed by the HD 6970. However, the GTX 560 Ti falls slightly behind the HD 6870. SLI’ing GTS 450 doesn’t save it at our resolutions although the GTX 460 gets a nice performance boost in SLI going from unplayable as a single video card to matching GTX 580 with nearly 100% scaling at 2560×1600. Our Radeons also benefit from CrossFiring them.
This covers our DX9 games and we note some variability with SLI and CrossFire Scaling. Let’s move on to DX10 and DX11 games to see if anything changes.
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.