Sign in with
Sign up | Sign in
Your question

A recommendation on how to measure actual PSU watt usage [SOLVED[

Last response: in Components
July 29, 2011 4:41:07 AM

hi folks, longtime site reader & first time poster.

i'm looking for a good way to measure actual, real-world PSU wattage. I've been running a Linux server in a closet now for about 5 years. (Arch Linux is the distro.) The experience has been an arduous but rewarding task, and it now runs as a NAT router/gateway, DNS server, DHCP server, Samba user-authenticating file server, local Apache test web server, and breeding ground for all manner of scripts and test programs that i've delved into all with SSH and torrent/xbox360 port forwarding.

The thing has a 150GB velociraptor system drive, 2 1TB WD greens, and a Seagate 7200RPM 1TB hard drive, with a grand total of 3150GB. ASUS M5N32-SLI deluxe, Sempron 1.8GHz, 4GB of 800MHz DDR2, and an ancient PCI ATI graphics card. I'm just curious as to how much watts the entire system is actually using, as it runs nearly 24/7/365. I've got a thermaltake 430w psu in it, but I've heard that most power supplies will only use what the whole system needs at a time, not 430W constantly.

Is there a way to see what the PSU is currently drawing using software, or possibly a hardware device I could buy that maybe could sit between the system and the wall and display the current wattage? Obviously I'd like to spend as little as possible, free even if it's a software solution.

Looking for recommendations from the community. Thanks

Best solution

a c 271 ) Power supply
July 29, 2011 4:45:46 AM

Just get yourself a little kill-a-watt meter, they will tell you current usage and they can also tell you how much you have used over time too.

Its not super cheap but its good and reliable, there isnt any software that can give you a good guess as to how much power you are using but it certainly isnt any where near 430W, probably less than 200W from the PSU so about 220W from the wall at peak.
July 29, 2011 4:49:53 AM

Ahh thanks for the awesomely fast reply. This was exactly the thing I was thinking of. I'm not too worried about accuracy, just looking for a ballpark figure.
good stuff
Related resources
Can't find your answer ? Ask !
a b ) Power supply
July 29, 2011 6:52:36 AM

Sounds like a Best Answer to me. Solved?
July 29, 2011 7:05:02 AM

Best answer selected by psycroptic_.
ngotcha. =)
a c 83 ) Power supply
July 29, 2011 4:37:15 PM

Remember that there is the matter of efficiency. The KaW will tell you how much power using from the wall, no argument there. But that is a different number then what your computer is using. If the KaW reports 150W being drawn, and your PSU is 50% efficient at turning AC into DC, then your computer actually only uses 75W, not the 150 you see. At low loads, I'd guess your around 70%, but I'm not sure because I don't know what PSU you have. If your looking for how much power you'll get billed for, the KaW will tell you. If you're wondering how much the computer uses, it will get you close but the real answer will be a bit less.
a b ) Power supply
July 29, 2011 4:53:00 PM

This topic has been closed by Mousemonkey