How Much Power Does Your Graphics Card Need?

Calculating Power Consumption Of The Entire System

In this table, you’ll find a small set of standard components that you can use as a general guideline for power consumption estimates. Standard CPUs use between 65 and 85 watts, while quad-core processors range from 95 to 140 watts.

Hard drives may vary greatly according to age and model; you can get by with 10 watts as an estimate, because drives rarely run simultaneously at full load. The maximum needed is 30 watts for a short time when booting the system; you should allow a safety buffer for this when estimating maximum power load capacity.

The chipset of a motherboard can be crucial, since integrated components such as sound, network, and additional controllers must be supplied with power. While Intel gets by with 20 to 30 watts overall, a larger SLI motherboard with an nForce chipset can easily require twice as much.

For a standard PC, having a powerful graphics card can easily account for 50% of the total power consumption. The values in the examples are measured liberally: the graphics card test system used has a dual-core CPU (65 nm), X38 chipset, two hard drives, and two memory modules, at 85 watts.