When I tested these cards I had to drag out a large screen CRT monitor, since even when benchmarking a single card it didn’t really start to break a sweat until I cranked the resolution up to 1,920 x 1,440. But when it comes to running two cards in SLi, even a resolution of 2,048 x 1,536 didn’t seem to cause any problems.
Let’s take a look at Half-Life 2 first. Here you can see that the cards are CPU limited in the lower resolutions. You can also see that there is a slight CPU overhead when running SLi, as the single card scores are actually higher at the lower resolution. Looking at the SLi scores you’ll see that the frame rate doesn’t drop below 100fps until you push the settings up to 1,920 x 1,440 with 4x FSAA enabled, and even then you’re still getting 95fps. Even running a single card you’re getting 66fps at the same resolution of 1,920 x 1,440 with 4x FSAA. But when you crank things up to 2,048 x 1,440 you start to see where the extra money you spent on an SLi solution is going – at this super-high resolution with 4x FSAA and 8x AF you’re still getting 68fps.
Of course I had to try out this setting, so I fired up Counter Strike: Source and started playing at 2,048 x 1,536 with 4x FSAA and 8x AF. The result was truly staggering, and I didn’t seem to suffer any major frame rate drops. Of course I had to tell everyone on the server what settings I was running, but no one believed me!
Loading up Far Cry showed a similar situation, but the most amazing observation is that the two cards in SLi were CPU limited all the way up to 2,048 x 1,536 if you run without FSAA or AF enabled – 1,024 x 768 scored 96.17fps while 2,048 x 1,536 scored 94.82fps. Even when switching on FSAA and AF, the SLi setup didn’t drop below 90fps until I hit 1,920 x 1,440 with 4x FSAA. Far Cry is definitely still a pretty demanding engine, because running a single card showed the frame rate dropping to 62fps at 1,600 x 1,200 with 4x FSAA and 8x AF. If you want to push the resolution higher than this, you’re going to have to turn the image quality settings off, but you will be rewarded with a silky smooth frame rate.