With news that Nvidia’s GeForce GTX 480 and 470 slurp down power, we expect modest consumption to be a real win for AMD. Sure enough, the 2GB Radeon HD 5870 is only moderately more needy than the 1GB card at idle. And while we measure about 28W higher power consumption under load, the Eyefinity 6 card still ducks under Nvidia’s GeForce GTX 470.
But those numbers only apply when a single monitor is attached. With six 22” displays connected to the Radeon HD 5870 2GB, idle system power jumps to 160W (in excess of a GeForce GTX 480 with a single display attached) and load power increases to 359W.
Adding a second Eyefinity 6 card in CrossFire and attaching a sextet of displays has a minor impact on idle power, bumping it up to 180W. But the shot to load power is more severe, peaking at 581W.
In all fairness (and in response to reader feedback from my GeForce GTX 480/470 story), I went back to test the power draw of the 480 with a second display attached, and it indeed jumps from 146W to 210W at idle. That’s the same roughly 30W difference between GeForce GTX 480 and Radeon HD 5870 that we saw with a single monitor attached.