Power Consumption:

On top of our graphics performance testing, we have also measured power consumption at both idle and load. For this we used our standard test system configuration listed earlier on in the review. In addition, we also tested the power consumption of the Radeon X1950 XTX and Radeon HD 2900 XT on our Asus Striker Extreme so that we could directly compare power consumption across all of the GPUs.

For our idle testing, we left the systems idling on the desktop for ten minutes, recording the average draw at the wall socket. For load testing, we used our benchmark routine from The Elder Scrolls IV: Oblivion and measured the peak power consumption in this section of the title. We tested the cards in a number of other scenarios and this proved to be the most intensive in all cases, so you can consider this to be a worst-case scenario.

Bear in mind that we have disabled all CPU-related power management options in the motherboard's BIOS so that we can highlight exactly how well the GPU's power management features are working (or not).


Idle power consumption on the Radeon HD 2900 XT isn't too bad in actual fact - much better than we were expecting, in fact. It consumes less power than BFGTech's GeForce 8800 GTS 640MB OC when it's idling on the Windows Vista desktop. Standard clocked 640MB GTS cards may consume less power than the Radeon HD 2900 XT in the same platform at idle, but performance won't be the same.

The Radeon HD 2900 XT CrossFire system also consumes a respectable amount of power at idle too – less than a GeForce 8800 GTX in the same motherboard. Interestingly, the difference in power consumption between the Intel D975XBX2 and the Asus Striker Extreme with the same graphics cards installed is a massive 55W. Urgh!


Unfortunately, efficiency is thrown out of the window when the Radeon HD 2900 XT is put under some load. It consumes more power than the GeForce 8800 Ultra in the same motherboard, and more than BFGTech's GeForce 8800 GTS 640MB and 320MB in a motherboard that has a 55W head start.

With a pair of HD 2900 XTs in CrossFire, things just get out of hand with power draw at the wall reaching 522W – 36W more than dual GeForce 8800 GTXs, even with the CrossFire rig using a motherboard with much lower power consumption. When it comes to power consumption under load, the Radeon HD 2900 XT can only be described as a hungry Honey Monster looking for more honey. I don't even want to contemplate the size of your electricity bill if you're Folding on a pair of these. Yow!