Power Consumption

On top of our graphics performance testing, we have also measured the power consumption of XFX's GeForce 9800 GX2 graphics card at both idle and load. For this we used the same systems that we have used for our 3D performance testing.

For our idle testing, we left the cards idling on the desktop for ten minutes, recording the average draw at the wall socket. For load testing, we used our benchmark routine from Crysis in DirectX 10 mode 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).



Once again, we see some impressive power consumption figures from AMD's Radeon HD 3870 X2. It's pretty frugal on the power when it’s running in idle mode and that’s all down to the ATI PowerPlay technology that the company implemented into its Radeon HD 3800 series hardware. Of course, the GeForce 9800 GX2 includes HybridPower technology, which will reduce its idle power consumption to an absolute minimum, but if you're not using a HybridPower enabled motherboard, this is what you're going to get.

Idle consumption is some 40W higher than the HD 3870 X2 and 10W higher than the GeForce 8800 Ultra, so it does a fairly good job of keeping power consumption down in idle (without HybridPower), but it's not brilliant compared to the 3870 X2. And, considering you're going to have a GPU that sits idle for at least 95 percent of the time, this number is probably more important to you if it's your only system.

Where things get interesting is with loaded power consumption - the GeForce 9800 GX2 consumes around 40W more than the GeForce 8800 Ultra and it also draws the same amount of power as a Radeon HD 3870 X2. However, what you've got to remember is that the GeForce 9800 GX2 delivers significantly higher performance than both of these cards in most scenarios and it uses 30W less power than a pair of similar-performing GeForce 8800 GTS 512MB graphics cards in SLI.