I have ventured across many sites in the last 3 days with no real definitive answers.

Attempting to price a near to true value of the running cost of a specific server based on consumption and not MAX wattage available.

I get the methods for working out cost of consumption. But a server running a pair of 800w PSU's for example does not use 1600w all of the time.

For this reason i cannot seem to identify what the actual consumption would be.

I thought the websites such as HP and DELL themselves would offer such information, yet sadly they do not.

I find this horrific yet that is of little importance i guess.

Budgeting for a new server is my task, but how do i know what the running cost of a specific serve is, for example:


And yes i know if i had it, i could plug it in to a consumption device, but i am not privileged enough to have that opportunity.

Is there a source for finding out the consumption of specific servers i am missing. Or is there a particular way to indeed calculate the consumption of a server, thus leading to an accurate calculation of running costs?


  • How much the server consumes depends on the programs you choose the run, and the data you push through those programs. How would HP or Dell know what your workload is going to be? – Joel Coel Jun 15 '15 at 0:11

The power consumption will vary widely depending on the load and activity on the server, measuring it with a consumption device can be very misleading. The running costs will thus vary a lot depending on how you're using the servers.

A servers's consumption will be below the rated wattage of the power supply, but you can't tell exactly how much under.

If the server has dual redundant power supplies you can take a single one into consideration (the server should be able to function with a single supply and the power it draws is roughly the same regardless of having a single supply plugged in or both). Technically there is a small difference due to the losses in the supply itself, but usually a very small percentage compared with the actual server consumption, if can be ignored in your calculations.

You might be able to ammend the rated power supply wattage a bit if your servers are not going to be fully equipped (i.e. all disk/card expansion slots, etc) - the power supplies should be able to handle those being equipped with typical devices. Unless the servers would require different models of power supplies with higher wattages to account for expansions.


I wouldn't recommend using that server today. The HP ProLiant DL585 G2 is a very old system (end-of-life: 2008). It is/was not a power efficient system.

Power utilization for that platform was usually 400-600 Watts for a server loaded with 4 CPUs, a moderate amount of RAM and a full internal disk array.

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I know this from observation/measurement of old ProLiant DL585 G2 systems I sold and deployed. You won't be able to find this information from the ILO 2 management processor of the HP server agents. This system does not support power utilization monitoring.

If you are being metered for power use, try using a different platform.

More modern servers have power meters in their out-of-band management solutions.

Another approach is to ask here or ask a datacenter/co-location provider about specific servers, as they'll have accurate real-world information.

If you come here with specifics, I'm sure someone can help you.


Not sure if you saw this site, or if it just doesn't quite meet what you're needing...

essa.us.dell.com seems to have almost exactly what you're asking for, unless I'm missing something.

Input your cost per kWh, select a system/solution, configure your usage (Transactional / Computational / Memory Intensive, and CPU load), and it gives you... Total power and current? Not sure why, but it doesn't look to display any cost-over-time estimates, even though it's just simple multiplication of the values it's already giving at that point...

  • There's also a pretty clear disclaimer along the lines of what others have said already, stating that the tool is only meant to assist in planning, and can't guarantee accuracy due to how vastly your results can very due to actual usage, blah blah blah... But it's the truth. Reminds me of predicting weather, but even less accurate. Don't bet solely on the forecast. dell.com/learn/us/en/04/campaigns/config_calculator – JimNim Jun 14 '15 at 5:21

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