How much power does a high end computer draw?

JonJ678

JonJ678

JonJ678

Soldato
Joined
22 Dec 2008
Posts
10,369
Location
England
To keep things remotely applicable to the everyday user, I'd like to restrict the question to above ambient cooling, one cpu, two graphics cards.

I'm reasoning about 200W for an i7, 150W per card, rest negligible. At a 80% efficient psu, that's (200+2x150)/0.8 = 625W from the wall at full load.

This site thinks my processor uses 300W, which I don't believe, and as far as I know it's about as good as online calculators get.

So, any ideas, measurements, or sources that might lead to the answer?

Also interested in any reasoning why you believe this figure will go up or down over the next couple of years.


Found a 280gtx review which disagrees with me: guru 3d.

Our test system contains a Core 2 Duo X6800 Extreme Processor, the nForce 680i mainboard, a passive water-cooling solution on the CPU, DVD-rom and a WD Raptor drive. The results:

* PC in Idle = 197 Watt
* PC 100% usage (wattage gaming Peak) = 530 Watt (SLI)
* PC 100% usage (wattage gaming Peak) = 749 Watt (3-way SLI)

guru 3d said:
GTX 280 can consume up-to 237 Watts per card when 100% stressed
Click to expand...


Found a source Here based on an es sample of an 920 that puts 3.8ghz, 1.5V at 311W.

Convincing article about processor power draw here. It's more complicated than taking the TDP value it seems.
 
Last edited:
Usually less than you think.
Only sure way is to get a power monitor £14.
Bonus is you can go round your house as well, checking other things out. If you are looking at cutting power usage.
 
i usually use the calculator on antec's site as a rough guide and that looks very similar to the one you have linked to.
you could check reviews on websites as most of their test systems will be i7 based and they usually test the power consumption at the wall in reviews for gfx cards.
 
AcidHell2 said:
Usually less than you think.
Only sure way is to get a power monitor £14.
Click to expand...

Ah, but then I'd also need a high end computer, which I don't have and think would cost more than 14 quid :p

Hotwired said:
It tells you 130W at stock for a i7 920. You'd get 300W for just the processor if you enter it as running at 4.5ghz on 1.4V.
Click to expand...

300W was 4.4ghz @ 1.45V which is what I was trying to get stable last week. Rule of thumb of 130 * (4400/2660)*(1.45/1,2)^2 suggests much the same figure so I daresay that's what it's based on, but that doesn't mean I believe it. For one thing there's the uncertainty associated with using the 130W TDP as a figure for power consumption.

Cheers for all the replies so far.
 
i7 920, ati5870, 6gb ram, the usual case, single harddrive and a burner.

Uses about 230w peak power draw, bittech/custom pc includes in its reviews this info.
 
I have an i7, 6Gb RAM, 2 x 275s running SLi, 8 x HDDs, 1000w PSU.... watercooled, and I have it plugged into a reader, I have not looked at the readings yet (too scared) but will look tonight and let you know...

Stelly
 
Last edited:
My i7 920 at 3.4ghz draws 130w, a top end pc with just a single top end card probably draws about 500w or around that.(talking a Radeon 5870.)

When you sli/crossfire cards or add more, the added cards do not use as much power as the original if i remember too.
 
I don't believe it's far off.

What it's doing is having ALL components under load to give a number, card reviews load the card, cpu reviews load the cpu.

I've just tried this one klick and it comes up as 431W minimum requirement. guru3d was getting 358W with the GPU under load and recommends a 500W PSU so the calculator falls easily into range.
 
I tested my the other week and this pulls around 480w with Prime and Win mark 2006 running at the same time.
I7 @ 4ghz 1.28v ~ and 5850 crossfire at stock speeds.

EDIT: I can't remember if I turned the monitor off though.
 
Dont have a power monitor, but ran that psu calculator, figure for my rig came out at 352w, currently have a 750w thermaltake toughpower installed, swapping this out for a corsair hx 850w though.
 
i just ran the psu calculator and it says i need at least a 455w psu, i run a coolermaster igreen 600w so i should be pretty well covered :)
 
My machine , including Moniotor, taking from the wall:
Idle 210W, Load 460W (Crysis) - never checked full load.
i7 @4GHz, GTX280 non OC, water loop
 
Last edited:
I fear this thread is going slightly offtrack. It doesn't matter what the online calculator says as we have no idea how reliable it is or what assumptions it's making to get to the final answer. So I'm not really interested in what a given piece of software thinks you need for a psu.


480W for i7 @ 4ghz and 5850 crossfire is a useful value, thanks RJC. Was this measured at the wall?

Good luck Stelly, definitely looking forward to that number. Did you really mean six 275s?

Cheers Blackwhite. What load was this under?
 
That site recommends I have a minimum of 603w PSU, but I do run a dual socket 1366 system. I'm going to buy one of these plugs and check what it actuallys pulls. Will let you know, even though you said just 1 cpu. Will be worth checking out anyway and adding to the results :)
 
You must log in or register to reply here.
Back
Top Bottom