jmke

Our tests will include the GeForce GTX 295 Quad SLI, GeForce 9800 GX2 Quad SLI, Radeon HD 4870 1GB Quad CrossFireX, and Radeon HD 4850 Quad CrossFireX.

Our first article explored 1 to 2 GPUs. The second looked at 1 to 3 and 2 to 3 GPUs. This one only focuses on the performance improvement from 2 to 4 GPUs. The reason for this is that there are no single GPU versions that exactly match half a GTX 295 or half a 9800 GX2. We can see when things don't scale and how they scale differently from 3 way by looking back at the previous article if people want, so having a lopsided analysis that included some metrics for AMD and not NVIDIA didn't seem quite right.

Our experience with stutter increased with the number of cards. Two way seems to be the smoothest of the multiGPU options, and we ran into the most problems with 4-way. Both AMD and NVIDIA showed some stuttering in Crysis, and there were issues in other games where scaling didn't happen the way we would have liked. Honestly, gamers who choose 4-way options will need to be hands on to get the best experience, disabling SLI and CrossFire when they get in the way of themselves.

http://www.anandtech.com/video/showdoc.aspx?i=3520&p=1

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