InsideHW pits the GTX 590 against the 6990.

"InsideHW.com has compared NVIDIA GeForce GTX 590 vs AMD Radeon HD 6990 graphics cards. Here is a quote from this review:

Every time that a new series of graphics cards is presented, it’s merely a matter of time before multi-GPU solutions are presented to be the cream of the crop of the current product gamma. These models don’t stay on the market for long, nor do they shift sizeable amounts of units sold, obviously, having in mind their outrageous price. Besides, the power efficiency of these models isn’t exactly something to be envied on, while the ludicrous dimensions and heating is also something to account for; besides the environmental threat they pose, these cards have to be provided with a large enclosure as well. So, why even bother to make them, one may ask..."



Link: InsideHW