Overclocking and Power Consumption
The EVGA e-GeForce 7900 GT CO SuperClocked being a pre-overclocked product, we just couldn’t expect it to be any good at further overclocking. The graphics processor indeed refused to work even at 570MHz and remained stable at 560MHz only. The graphics memory could be overclocked to 800 (1600) MHz; at higher frequencies various image artifacts appeared. It’s all right for the memory since the installed GDDR3 chips are rated to work at 700 (1400) MHz. We set an additional 120mm fan to blow at the card during our overclocking experiment, but the result was a failure anyway.
Then we measured the power consumption of the graphics card using a special testbed with the following configuration:
- Intel Pentium 4 560 CPU (3.60GHz, 1MB L2 cache)
- Intel Desktop Board D925XCV
- 2 x 512MB PC4300 DDR2 SDRAM
- Samsung SpinPoint SP1213C hard disk drive (Serial ATA-150, 8MB buffer)
- Microsoft Windows XP Pro SP2, DirectX 9.0c
We measured the power consumption of the card with a digital multimeter Velleman DVM850BL (0.5% measurement accuracy). To put a Peak 3D load on the card we ran the first SM 3.0 graphics test from 3DMark06 in a loop at 1600x1200 resolution and with enabled 16x anisotropic filtering. Then we created an extremely high 2D load by launching the 2D Transparent Windows test from Futuremark PCMark05. Here are the results:
The new 0.09-micron graphics processor from Nvidia again proves how little power it needs to operate. The EVGA card consumes only 8.5W more than the standard GeForce 7900 GT despite the considerable difference in their clock rates. The GeForce 7800 GT and Radeon X1800 XL have roughly the same power consumption but they have much humbler technical characteristics in comparison with the EVGA e-GeForce 7900 GT CO SuperClocked.