Some of us who've been in the PC gaming scene for a while now may remember the days of the dual-GPU versions of the (then) popular 3DFX Voodoo series cards. They were quite the power-house at the time, but were considered by many to be a bit on the excessive side. Well, those glory days are back, with Gigabyte's new offering: the Dual-GPU NV6600. According to Gigabyte, this baby will outperform both NVidia and ATI's current flagship products, while being priced significantly less than either. This is accomplished by using on-card SLI and 256mb of fast DDR3. Sweet! -AT
At present, you'd need a multiprocessor system in order not to bottleneck on the CPU with a card any better than that. A dual-GPU 6800GT would just be wasteful until CPUs get better.
But then again this is only 1 single card with 2 GPUs not 2 separate cards which would probably cause a bottleneck. So Something high end like an A64FX 55 or higher would do the job without too many problems. However dual CPUs would be the best.
Yes, it'll be a large performance increase, but only at very high resolution, and/or with high antialiasing. Still, I wish I could afford something like that!