With SLI and CrossFire we all hoped to see direct scaling so that a quad GPU setup would be somewhere in the neighbourhood of 4x better than a single GPU.  That has proven to be incorrect, not only is the scaling nowhere near that it has been discovered that in some cases going beyond 2 GPUs can actually reduce performance.  

As the hardware and drivers evolve, it is worth revisiting the scaling performance of both AMD and NVIDIA which is why [H]ard|OCP grabbed two GeForce GTX 590s and two AMD Radeon HD 6990s, both dual GPU cards.  In three of the five games tested they ran into at least one issue, a strike right off the bat.  Read on to see how they rate the value of the two manufacturers based on the performance they saw once they’d resolved the problems.

"How does NVIDIA’s GeForce GTX 590 SLI Quad-GPU compare to AMD’s Radeon HD 6990 CrossFireX Quad-GPU? We will find out if these "if-money-didn’t-matter dream video card setups" will deliver the gameplay experience we all expect."

Here are some more Graphics Card articles from around the web:

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