I recently built myself a new Linux Server with a Core 2 Duo 1,83 GHz CPU and a nVidia GeForce 7200LE graphics card, which was the cheapest passively cooled card I could find. I've measured power draw of the system and it seems to draw about 95 Watts.
The graphics card seems to generate quite a bit of heat though, I don't even have a monitor, mouse or keyboard connected to the machine so this seems quite unnecessary.
Can I underclock or even power down the graphics card somehow to conserve energy?
Update: After removing the graphics card and undervolting the CPU from 1.25V to 1.1V (seems stable), power usage has dropped to 70 Watts. Thanks everyone.