Conclusion: Nvidia's dual-GPU card, the GeForce GTX 590, is undoubtedly powerful. But while it's quieter than AMD's own double-barreled Radeon HD 6990, that card delivers better overall performance for the same price.
Pros: Excellent performance. Quieter, shorter than AMD's competing card. Can control three monitors with DVI connectors.
Cons: Expensive. Performance surpassed by competition. An energy hog under load. Requires two eight-pin power adapters, hefty PSU.