How Much Power Does Your Graphics Card Need?

Features
By Tino Kreiss
published

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.

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ComponentPower Consumption (Watts)
CPU Intel Pentium 4 (Prescott) 3.2 GHz84
CPU Intel C2D E2140-222065
CPU Intel C2D E675065
CPU Intel C2Q Q660095 or 105
CPU Intel C2D E7200-730065
CPU Intel C2D E8200-860065
CPU Intel C2Q Q9300-965095
CPU Intel Core i7 92085
CPU Intel Core i7 94092
CPU Intel Core i7 965 Extreme100
CPU AMD Athlon 64 3800+ EE62
CPU AMD Athlon 64 X2 4800+ EE65
CPU AMD Athlon 64 X2 4800+89
CPU AMD Athlon 64 X2 6000+125
CPU AMD Phenom X395
CPU AMD Phenom X4 9100e-9350e65
CPU AMD Phenom X4 9500-975095
CPU AMD Phenom X4 9750-9850 Black125
CPU AMD Phenom X4 9950 Black 140
Hard Drive 2.5"2 to 6
Hard Drive 3.5"10 to 30
DVD Drive5 to 12
Mainboard20 to 60
1 Memory Module3

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.

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Example For  A Standard PC Without Graphics CardPower Consumption
Dual-Core CPU65
Motherboard, Intel Chipset20
2 Memory Modules6
2 Hard Drives20
Drive + Burner20
Total Power131
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Example For A Power PC Without Graphics CardPower Consumption
Overclocked Quad-Core CPU130
Motherboard, Nvidia Chipset60
4 Memory Modules12
4 Hard Drives40
Driver + Burner20
Total Power262
Tino Kreiss
129 Comments Comment from the forums
  • Inktfish
    Could you please add the Radeon 4830? :)
    Reply
  • sepuko
    Took the words right out of my mouth.
    Reply
  • since Core i7 920 has TDP = 130W, how can it consume 85W only?
    Reply
  • 1.21 Jigawatts !!!
    Reply
  • nukemaster
    This article was due. No more you need an 800 watt psu for the 4870 , core2 quad ad 1 hard drive anymore :p

    Guest11since Core i7 920 has TDP = 130W, how can it consume 85W only?The TDP is more of a design thing. Almost all of Intels initial Core2 line had a TDP of 65 watts yet many took much less power. Intel gives a worst case of that type number and does not measure every cpu.

    AMD does the same thing. They listed almost all the initial Athlon 64's at 89 watts yet many did not take that or give off that amount.

    zxv9511.21 Jigawatts !!!You act like you would need a small fusion reactor or maybe a bolt of lightning to get that?
    Reply
  • neiroatopelcc
    So my system actually has a too big power supply to be effective?
    I'm running a 3,4ghz c2d with 5x500gb sata drives, a dvdrw and a 4870 on a p35 board.
    According to the article that's not going to draw the ~400W needed to get within effective range of my corsair 620 ....
    Reply
  • cynewulf
    There's a mistake in the power under load for the 3870X2. It shows the same as the idle consumption. If only that were true! :D
    Reply
  • Inneandar
    The TDP (thermal design power) is meant to be a guideline for the cooling solution, not the power consumption. To qualify for a cpu with a TDP of 120W, a cooler must be able to dissipate 120W. Practically, of course, this means it is an upper bound to (sensible) power consumption.

    also small note: Is it just me or is it strange to see the 260 SLI consume more than the 280 SLI. maybe in need of a beefier test scene...
    Reply
  • zodiacfml
    nice collection of data. i hope many learn from this and avoid recommending too powerful supplies.
    Reply
  • roofus
    better off with too much power supply than not enough. at least if you over-spec the power supply you leave some breathing room for any additional components.
    Reply