I'm curious if anyone has data on sources of power draws on a typical server computer. On an AMD single dual core processor system that we start up in an energy saving mode at 1.8 GHz, we are measuring 350 watts in idle state. No hard drives are installed. The processor itself is specified to run at around 95 watts under load, so the additional 250 watts of energy use surprised me a little. How much of the remaining energy utilization is going to chipsets and how much is going to fans?
Energy Utilization on Efficient Dual Core
Aug 10, 2007
6 Replies
Are you measuring watts or volt-amperes?
How are you measuring the power used?
Servers tend to have many fans. You could have 50+ watts just in fans. The chip set should use around 15-20 (wag). John
I'm using a LaCrosse Cost-Control unit whose power page says "Watts". Who knows how they implemented it, but the measurement is taking place between the outlet and the plug going into the server.
I have no idea what the power factor on an HP DL385 G1 server is.
And maybe 20 watts per PCI card times 3 would give another 60 watts. So
95 + 50 + 20 + 60 = 225, which still leaves about 125 watts unexplained.
Most modern computers utilise PSUs with active power factor correction (APFC) look for "PFC" or "APFC" on the PSU label. If is it then the PF is going to be around 0.9 to 0.95. A standard PC PSU is generally reckoned to be around 0.7, which is pretty bad, when you consider a drop in PF from 1 to 0.9 means a reduction in efficiency of about 15%.
A reduction in power factor doesn't imply anything about efficiency. They are nothing to do with each other.
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