SLI/CF testing? Best method?

[draemn]

Hey,

As I'm starting to look at benchmarks about multi-GPU performance (I have an itch to go surround, but I'm resisting for now), I begin to wonder how the best way to judge performance is?

Obviously, if I'm thinking surround, higher resolution, but after reading some pitiful (results) reviews on 3-way GPU benchmarks, I began to wonder if the fatal flaw of most of these reviews is not using a high enough resolution? Even if we run a i7-2600k @ 4.0 Ghz or a i7-750 @ 3.8 Ghz, is that enough to remove the CPU bottleneck @ 1920x1080, or even 2560x1600?

Will we see the best GPU scaling on a 3-way monitor set-up vs. SR-2 with 2 x i7-990x @ 4Ghz each @ 2560x1600?

[Arinoth]

The bottleneck for multi-monitor I have found is still on the gpu side either with the overall bandwidth for pci-e slots or how fast the two can communicate and process images as the same time. I've run games on an e6400, i7 940 and a 2500k all at different clocks and i haven't noticed a notable difference in frames (or benchmarking results, though the e6400 did score significantly lower) between the i7 940 at 3.8ghz an the 2500k running stock.

You must remember that all newer platform, especially the 1366 is designed for high bandwidth for multiple pci-e devices, namely graphics cards, and really never sees a bottleneck at all. As for 1156 and 1155 i doubt eithe running at those speeds would cause a bottleneck even at 5760 x 1080, however i can only speak from personal experience and the minimal benchmarking i've done (typically just game and monitor fps)

[draemn]

Yeah, I'm just curious because everyone uses such vastly different test benches. Some use the X58 platform and usually get around 3.8 Ghz, some use P55, and others use the P67... I also find that there is a huge difference in CPU speeds as there are clocks from 3.2 Ghz to 4.2 Ghz depending on the review.

Any thoughts on what CPU/clock speed is needed to remove a CPU bottle neck when you get into the high end SLI/CF realm?

[JJThomp]

Originally Posted by draemn

Yeah, I'm just curious because everyone uses such vastly different test benches. Some use the X58 platform and usually get around 3.8 Ghz, some use P55, and others use the P67... I also find that there is a huge difference in CPU speeds as there are clocks from 3.2 Ghz to 4.2 Ghz depending on the review.

Any thoughts on what CPU/clock speed is needed to remove a CPU bottle neck when you get into the high end SLI/CF realm?

It depends on the game but 4 cores at 4.2 ghz should be fine for almost everything.