Power Specs for Servers

[Jim Mulgrew]

I was hoping someone might be able to clarify something for us. We just want to make sure we are interpreting things correctly for planning purposes. We are investigating the power and cooling situation at the datacenter yet again and one of our scenarios encompasses how much Watts we would “save” by shutting down some of the DEV/QA servers in the environment there. We were banging out the numbers yesterday and it just didn’t seem right. I did some looking on the HP website at some of the quickspecs for retired servers. I’m going to use the quickspec for a DL380 generation 1 for example:

http://h18000.www1.hp.com/products/quickspecs/10495_na/10495_na.HTML#TechSpecs


If I go to the techspecs section, I see a rated input requirements (per power supply) of 432W, I also see power supply output power (per power supply) of 275W “ready state” and 305W “peak power”.

As I interpret it, if I shut down this server that has 2 power supplies in it, my “savings” would be 864W. Is that a correct s

[Derek_31 · Accepted solution]

What the server actually uses in terms of power is nearly always a lot less than the rated specs. They make cheap devices that measure the power that a device uses. "Watts Up" is one that we use.

If a server has two power supplies, then it can run on one. This means the total power the server can use is no more than the maximum rating of one power supply. Depending on what options you have installed (memory, HDs, PCI cards, processor speed), the power draw might be a lot less.

[kcpant]

hi Jim,

Derek is right, even if you are using 2 power supplies ( I believe it's 1+1 redundent power system), you might be using something between 275W and 305W.

thnks & regards