[H]ard|OCP has had a chance to play with high end GPUs, in multiples, which means setting up dual GPU systems to test.  Of course to truly push these cards you need to be feeding multiple monitors which is why most tests were run at a resolution of 5760×1200, as in three 1920×1200 monitors.  From their testing they saw a pattern emerge based on memory bottlenecks.  In some games it seemed that the extra memory present on the AMD cards let them soar ahead, however on any game in which the bottleneck did not rear its ugly head the nVIDIA cards were clear winners. 

Not only is the price a serious consideration when upgrading, your choice of game may also affect the GPU to invest in.
“Ever wondered how the new Radeon HD 6970, Radeon HD 6950, GeForce GTX 580 and GeForce GTX 570 perform when paired up with a second card? We did, and we have evaluated all four combinations in AMD Eyefinity and NV Surround resolutions.”

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