Measuring power consumption

potsy · Post by **potsy** » Thu May 08, 2008 6:16 am

Hi all, I thought I would measure the power consumption of my system using a kill-a-watt thing, but I can't get any difference between idle and load. It generally fluctuates between 81-97w. I tried CPUstabilitytest and ran my protools software at full tilt to make sure both drives were going (and speedfan said 100% cpu usage). But no difference - still fluctuates between 81-97w.

That can't be right can it? I tried intel's TAT but that doesn't work on the G33mobo yet. Is there some other software I should use to simulate load?

Cheers
Potsy
System specs are here, except that I now have a GA-G33M-DS2R Mobo and E8200cpu: potsy's puter

amyhughes · Post by **amyhughes** » Thu May 08, 2008 9:00 am

A 16W spread between idle and load is perfectly reasonable for a low-power CPU. I can get that with an undervolted E8400. For a stable high-power load, run prime95. It won't exercise your disks but it'll tell you the spread between idle and load for your processor.

Also, running something other than a CPU test at the same time as the CPU test will likely decrease, not increase, the total load.

scdr · Post by **scdr** » Thu May 08, 2008 10:24 am

Are you sure that getting it loaded is the problem?
Idle power looks a little high - is speedstep, etc. enabled?
Checked that don't have much running in background, etc.

amyhughes · Post by **amyhughes** » Thu May 08, 2008 11:20 am

amyhughes wrote:A 16W spread between idle and load is perfectly reasonable for a low-power CPU. I can get that with an undervolted E8400.

I missed the part about your swapping the CPU for an E8200. You'd have to have it undervolted and underclocked to see just 16W spread between load and idle. Scdr is right. Your idle number looks high. I think you should be seeing less than 60W idle.

potsy · Post by **potsy** » Thu May 08, 2008 3:59 pm

Oooops, red face, sorry, sorry, sorry. I had left a compressor plugged in to the same outlet in the back of my rack. So... when the power meter is measuring the computer (on its own) it reads:
54w at idle, nice and stable;
60-67 with protools loaded; and
60-67 with Prime95 running.

Now that looks better. Sorry to take your time with something so silly. And thanks for your help - scdr as soon as I read your post I twigged. Nothing running in the background, but there sure was something running in the foreground!

I'm pretty happy with those numbers. I've only got a 200w psu and I've always thought it might be a bit light on. But it's easily enough. Which makes me wonder why any ordinary user would have a fan in their psu. It's just not necessary is it?