Power, Heat and Noise

Here' we'll take a look at a few of the environmental effects the graphics board has on its surroundings and the rest of the system by looking at the Power usage, Heat and Noise outputs. Due to the measuring equipment we'll not be able to give definitive quantities solely pertaining to the graphics board, as we are unable to entirely isolate it, so each of the metrics are taken at a system level, however where the same system is used and only the graphics board swapped out we can begin to gauge the effects the boards have in relation to one another. In this instance the core temperature is taken directly from the value reported by the driver control panel.

For the testing of all the elements we took the idle noise level results shortly after boot-up, by placing the noise level meter at the bottom of the case, the case side was then placed on and the power and temperature readings were taken. 3DMark03's graphics intensive Game Tests were then looped through 4 times, to load up the graphics, and then on the fifth run of Game Test 2 the power reading was taken, then the core temperature read immediately after dropping out of the 3D scene, the system case temperature noted, and finally the case side removed and the noise level measured. 3DMark03 is used as it has a fairly low CPU utilisation, placing much of the emphasis on the graphics capabilities.

System Power Use (W) 7800 GTX 512MB 7800 GTX 256MB 6800 Ultra 256MB
Idle 136 135 146
Use 320 288 267
Increase 184 153 121

Not unexpectedly the system power draw is greatest under load with the GeForce 7800 GTX 512MB at 320W, some 32W higher than the peak on the 256MB board.

System Temperature (Degrees) 7800 GTX 512MB 7800 GTX 256MB 6800 Ultra 256MB
Idle 27 27 27
Use 32 30 32
Increase 5 3 5

The system temperatures were similar, although the GTX 512MB shares the highest system temp with the 6800 Ultra.

Core Temperature (Degrees) 7800 GTX 512MB 7800 GTX 256MB 6800 Ultra 256MB
Idle 42 50 60
Use 71 74 70
Increase 29 24 10

Interestingly the 512MB GTX displays the lowest idle core temperatures and is still lower than the GTX 256MB board at high loads, which would tend to indicate that the cooler on the GTX 512MB board is very effective at moving heat away from the core, or at least very much mores than the single higher cooler on the GTX 256MB board.

System Noise (db) 7800 GTX 512MB 7800 GTX 256MB 6800 Ultra 256MB
Idle 59 60 69
Use 71 71 72
Increase 12 11 3

Finally we see that with regards to the system noise, the GTX 512MB board is adds no more noise in this instance than the GTX 256MB board, and both of these are a little quieter than the 6800 Ultra.