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Calculating Power Consumption Of The Entire System

How Much Power Does Your Graphics Card Need?
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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.

Component
Power Consumption (Watts)
CPU Intel Pentium 4 (Prescott) 3.2 GHz
84
CPU Intel C2D E2140-2220
65
CPU Intel C2D E6750
65
CPU Intel C2Q Q6600
95 or 105
CPU Intel C2D E7200-7300
65
CPU Intel C2D E8200-8600
65
CPU Intel C2Q Q9300-9650
95
CPU Intel Core i7 920
85
CPU Intel Core i7 940
92
CPU Intel Core i7 965 Extreme
100
CPU AMD Athlon 64 3800+ EE
62
CPU AMD Athlon 64 X2 4800+ EE
65
CPU AMD Athlon 64 X2 4800+
89
CPU AMD Athlon 64 X2 6000+
125
CPU AMD Phenom X3
95
CPU AMD Phenom X4 9100e-9350e
65
CPU AMD Phenom X4 9500-9750
95
CPU AMD Phenom X4 9750-9850 Black
125
CPU AMD Phenom X4 9950 Black
140
Hard Drive 2.5"
2 to 6
Hard Drive 3.5"
10 to 30
DVD Drive
5 to 12
Mainboard
20 to 60
1 Memory Module
3


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.

Example For  A Standard PC Without Graphics Card
Power Consumption
Dual-Core CPU
65
Motherboard, Intel Chipset
20
2 Memory Modules
6
2 Hard Drives
20
Drive + Burner
20
Total Power
131
Example For A Power PC Without Graphics Card
Power Consumption
Overclocked Quad-Core CPU
130
Motherboard, Nvidia Chipset
60
4 Memory Modules
12
4 Hard Drives
40
Driver + Burner
20
Total Power
262
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Top Comments
  • 10 Hide
    nukemaster , January 21, 2009 10:59 AM
    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?
Other Comments
  • 7 Hide
    Inktfish , January 21, 2009 8:52 AM
    Could you please add the Radeon 4830? :) 
  • 3 Hide
    sepuko , January 21, 2009 9:13 AM
    Took the words right out of my mouth.
  • -5 Hide
    Anonymous , January 21, 2009 10:06 AM
    since Core i7 920 has TDP = 130W, how can it consume 85W only?
  • -3 Hide
    Anonymous , January 21, 2009 10:46 AM
    1.21 Jigawatts !!!
  • 10 Hide
    nukemaster , January 21, 2009 10:59 AM
    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?
  • -1 Hide
    neiroatopelcc , January 21, 2009 11:39 AM
    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 ....
  • 2 Hide
    cynewulf , January 21, 2009 11:46 AM
    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 
  • 3 Hide
    Inneandar , January 21, 2009 11:48 AM
    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...
  • 2 Hide
    zodiacfml , January 21, 2009 11:53 AM
    nice collection of data. i hope many learn from this and avoid recommending too powerful supplies.
  • 0 Hide
    roofus , January 21, 2009 12:12 PM
    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.
  • 0 Hide
    kschoche , January 21, 2009 12:34 PM
    neiroatopelccSo 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 ....


    Absolutely Correct!
    If you add all of those components together, and get 400W, and your PSU is only 75% efficient at that level, you're actually consuming ~500W and your PSU is eating that extra 100W. Though if you have a modern PSU, its usually not that bad, but goes to show that idiots who buy 1200W PSU's because it has a big number really are just that, idiots.
  • -1 Hide
    zodiacfml , January 21, 2009 12:51 PM
    yes if you're planning to add a video card but adding a couple of hard drives, dvd drive, or upgrading the processor won't require more than 100W allowance.

    roofusbetter 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.

  • 0 Hide
    one-shot , January 21, 2009 2:01 PM
    kschocheAbsolutely Correct!If you add all of those components together, and get 400W, and your PSU is only 75% efficient at that level, you're actually consuming ~500W and your PSU is eating that extra 100W. Though if you have a modern PSU, its usually not that bad, but goes to show that idiots who buy 1200W PSU's because it has a big number really are just that, idiots.


    Let's take a step back. If his PSU is 400W and it is 75% efficient, then it draws 533.3W at maximum power draw. You are somewhat close, but you generalized. Different PSU's are more efficient at different load percentages, but 75% sounds alright for an older PSU. His Computer draws 400W and his PSU draws 533W from the receptacle on the wall.
  • 3 Hide
    billiardicus , January 21, 2009 2:09 PM
    Toms,

    Great article. This is exactly why I visit your page everyday. How about adding the GTX 295 and 285 in single and SLI configurations to the list? Hey, somebody has to ask right? :) 
  • -4 Hide
    hyteck9 , January 21, 2009 2:29 PM
    Where is the Nvidia 295?
    I think the 295 with an i7 OC'd to 4Ghz is going to be a pretty standard choice in the coming months... add a hard drive and a DVD-burner and your looking at 600WATTs at full load... so 800WATT PSU would be the right choice, yes?
  • 3 Hide
    Niva , January 21, 2009 2:33 PM
    Well I learned something, I always thought that PSU ratings are based on what they can suck out, not what they put out to the computer components which they power... now that I'm looking at this article I feel pretty stupid for thinking this all these years.
  • 4 Hide
    Pei-chen , January 21, 2009 2:49 PM
    One of the best articles ever. I hate proving myself when I tell people that using an inefficient video card will increase their electric bill by $50 vs. an efficient card. An idiot actually told me that the difference between a GTX 260 and 4870 running 24/7 at idle for a year is less than $10.

    My system:
    ASUS P5B Deluxe WiFi-AP
    E6400 @ 2.56Ghz @ 1.135v with Speedstop enabled
    8GB OCZ PC2-6400 RAM @ 1.8v
    Arctic Cooling Freezer 7 Pro with PWM enabled
    Antec NeoPower 550 PSU
    2x Seagate 7200.11 1.5TB drive
    1x Toshiba SATA DVD+/-RW drive
    GIGABYTE GV-R485OC-1GH Radeon 4850 @350 core/500 ram

    The idle power consumption at plug is 1.06A. Gaming load is about 1.71A with the Radeon overclocked to 730 core and 1130 ram. The 4850 consumption should be lower than typical 4850s because it uses GIGABYTE's custom PCB. Clearly my PSU is overkill as I only load it between 20~40% but it is not that easy to find good quality small PSU two years ago. Good thing it’s efficient.
  • 3 Hide
    Anonymous , January 21, 2009 3:12 PM
    This is an exellent article!

    There has been way too much bull about needing a 500 watter or more for a regular board, cpu and single graphics card. Its also great to have figures to compute total cost of ownership per GPU. The PC i game on is more on then off, so this info is significant. Thank you.
  • 3 Hide
    Anonymous , January 21, 2009 3:16 PM
    Interesting article.. it should be noted that those of us with Geforce 2** cards and two monitors active will always be drawing the full 3D load of powe.

    There is a bug in the latest two WHQL drivers which causes throttling to not occur even if there are no 3D applications active.
  • 7 Hide
    hyteck9 , January 21, 2009 3:30 PM
    Dont forget to spend $500 on a UPS that can handle your 800-1000 watt power supply!
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