SLI vs. CrossFire, Part 1 – mid-range multi-GPU scaling & value
Lost Planet
Lost Planet: Extreme Condition is a Capcom port of an Xbox 360 game. It takes place on the icy planet of E.D.N. III which is filled with monsters, pirates, big guns, and huge bosses. This frozen world highlights high dynamic range lighting (HDR) as the snow-white environment reflects blinding sunlight as DX10 particle systems toss snow and ice all around.
The game looks great in both DirectX 9 and 10 and there isn’t really much of a difference between the two versions except perhaps shadows. Unfortunately, the DX10 version doesn’t look that much better when you’re actually playing the game and it still runs slower than the DX9 version. We use the in-game performance test from the retail copy of Lost Planet and updated through Steam to the latest version for our runs. This run isn’t completely scripted as the creatures act a little differently each time you run it, requiring multiple runs. Lost Planet’s Snow and Cave demos are run continuously by the performance test and blend into each other.
Here are our benchmark results with the more demanding benchmark, Snow. All settings are fully maxed out in-game including 2x or 4xAA/16xAF. Let’s start with 1920×1200 resolution with 2xAA.
Now at 1680×1050 and with 4xAA:
The HD 5870 is edged by the GTX 480 which in turn is beaten by the GTX 570 while the GTX 580 convincingly takes the single card crown. However, the HD 6870 is faster than our GTX 560 Ti and CrossFired HD 5870s and 6870s also beat GTX 560 Ti SLI. However, we note another oddity in otherwise near-perfect CrossFire scaling where in one case, the scaling is slightly greater than 100%. It is a tiny amount of around 101% and could easily be attributed to many. We will attempt to cover this in our conclusion.
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.