NVIDIA GeForce 6800 GT
The NVIDIA GeForce 6800 GT is a slower and cheaper model, but based on “healthy” chips with all the 16 pixel pipelines and GDDR3 memory. I’ve got a GeForce 6800 GT-based card from Leadtek for my today’s tests. It is the WinFast A400 GT TDH model:
This graphics card uses the same design as the GeForce 6800 Ultra, but has only one additional power connector. The GeForce 6800 GT GPU and 256MB of GDDR3 memory are clocked at 350/1000MHz, respectively. This card quite naturally had a better overclockability than the top-end product. I reached 420/1150MHz frequencies at overclocking, which are higher clock rates than the GeForce 6800 Ultra’s regular ones.
The results of my measurements follow:
The GeForce 6800 GT consumes much less power than the GeForce 6800 Ultra: 55.39W in the Burn mode and 23.41W in the Idle mode. Two factors contribute to the lower power consumption of the device: 1) the GeForce 6800 GT has lower GPU and memory frequencies than the 6800 Ultra and 2) the GPU voltage is lower here, too. According to my measurements on the Leadtek card, the GPU voltage was 1.35v against 1.45v on the 6800 Ultra card. The effect of the reduced voltage is especially noticeable at overclocking: although the GeForce 6800 GT overclocked above the standard frequencies of the GeForce 6800 Ultra, its power consumption remained at a lower level.
The specifics of the power consumption remained the same, though. The GeForce 6800 GT doesn’t practically load the AGP slot, but takes a bulk of its supply from the +12v power rail.
The GeForce 6800 GT has a little higher power consumption than its direct market competitor, the ATI RADEON X800 Pro; the difference is smaller between them than between the two topmost products. The GeForce 6800 GT and the RADEON X800 Pro consume 55.39W and 48.2W, respectively, in the Burn mode, and 23.41W and 15.1W in the Idle mode.