IIRC, each 12V wire is rated for 75W, and there's three per connector, so technically each connector is good for 225W. So the board is geared for 75W (PCIe slot) + 225W + 225W power consumption = 525W total power consumption. However, it's important to note here that this is an actual hardware limitation, and extreme overclocks, which will definitely pull more than that, will actually be dangerous. The fact that a "factory" overclocked 6990 (via AUSUM BIOS) consumes ~440W does not leave a lot of headroom.
Thanks for the info, it's extremely helpful :thumbsup:. There looks to be a significant deficit there. If you have time, would it be possible to bench one of your GTX 480's at those speeds to we can look at scaling? I wonder if the reduce clocks would also effect that.
"Mixed reviews" is one review to you? [H] seems to disagree:
The point is, the 6990 offers currently unparalleled performance in a single card, and is actually quite power efficient:
http://www.techpowerup.com/reviews/ASUS/Radeon_HD_6990/23.html
You'll notice that the 6990 is still more power efficient than any card offered by NVIDIA @ 2560x1600 (and if you're buying a 6990 to play at a lesser resolution, "you're doing it wrong"). Its main problem is noise, which by all reports is ungodly.
That is impressive if NVIDIA pulls it off :thumbsup:. The axial style fan will most certainly be quieter than AMD's radial design. It's interesting how tables have turned this time: the GTX580 might end up being a decent second place card if it's quieter and performs only a bit slower. Also, the smaller footprint is more than enough to win some over. Very interesting

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