X-bit labs

Power Consumption of Contemporary Graphics Accelerators. Part II: NVIDIA vs. ATI (page 4)

Category: Video

by Tim Tscheblockov

[ 08/22/2004 | 12:11 PM ]

NVIDIA GeForce 6800

This is the slowest model based on the NV40 architecture. The GeForce 6800 uses the same dies as the faster products, but has only 12 out of 16 pixel pipelines enabled. The GeForce 6800 also has lower frequencies compared to the 6800 GT. This GPU is represented by the Galaxy Glacier GeForce 6800 graphics card:

The design of GeForce 6800-based cards differs from the GeForce 6800 GT/Ultra reference design. The device from Galaxy uses a cooler from Arctic Cooling, which resembles the cooler of the HIS Excalibur RADEON X800 Pro from my first report (see this article for details), instead of the standard cooling system. The card is based on the GeForce 6800 GPU and has 256MB of DDR SDRAM, rather than high-performance GDDR3, on board.

The nominal clock rates of the Galaxy Glacier GeForce 6800 are 350/700MHz – as you see, the core frequency is originally 25MHz higher on this card than the recommended 325MHz. The graphics memory overclocked well, while the GPU – less successfully. The maximum stable frequencies were 375/900MHz.

The results of the test:

The NVIDIA GeForce 6800 eats less energy than the GeForce GT as it has lower frequencies and the GPU voltage (it equals 1.22v on the Galaxy card against 1.35v on the GeForce 6800 GT). As a result, without overclocking, the card consumes 16.96W in the Idle mode and 38.88W in the Burn mode.

The tabled results:

The voltage regulators of the GPU and memory on the GeForce 6800 are built in a different way than in the top-end models. This is clear as we have a different PCB design here as well as consumption currents. The GeForce 6800 uses the power provided by the AGP slot more actively than the GeForce 6800 Ultra even, eating a total of 7W in the Burn mode through the 3.3v, 5v and 12v lines of the AGP. However, the main load still rests on the 12v line which goes through the additional power connector. In the Burn mode, the consumption on this line grows up to 23.62W with a current of 2.01amp.