Multi-GPU Question

[Jayhawk]

Not sure where to put this or how to explain this. When running SLI/Crossfire, the GPUs work together, but how? Do they split it and each run half a frame, or do each render every other fame? I know both techniques exist , that the first is the more efficient, and think that the latter is the most commonly used. I just want to know which of the two is the commonly used one. 

[ShadowCaptain]

Not sure where to put this or how to explain this. When running SLI/Crossfire, the GPUs work together, but how? Do they split it and each run half a frame, or do each render every other fame? I know both techniques exist , that the first is the more efficient, and think that the latter is the most commonly used. I just want to know which of the two is the commonly used one. 

 

(sometimes you can swap between methods in the control panel for the GPUs)

 

Alternate frame rendering is the most commonly used, that is why crossfire/SLI can suffer from microstuttering at low framerates

 

basically the game is loaded into the GPU VRAM which is mirrored across the 2 cards, and they take turns rendering alternate frames for a theoretical 2x performance boost

 

If they were rendering half a frame each, any latency would create horrible screen tearing

[Jayhawk]

Thanks, however, screen tearing isn't a "big" issue with certain methods. I saw a video that used a "new" method of splitting frames that manages to look identical to the alternate frame rendering method, no tearing whatsoever. I can't remember what the video is called, but it was on Civ 5. They only showed it on Linux since it was easy for whatever reason. Probably since Linux is more edit friendly. The did show on single, triple, and even 6-way monitor setups.