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I'm trying to get some rackspace and buy an appropriate server. I've got a quote for 1/4 cabinet which includes 0.5kw of power. How do I know how much power my server will use...(e.g. I've looked on the dell website and cannot see this listed anywhere)

Thanks, D

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Which server are you thinking of buying? – Tom O'Connor Apr 10 '12 at 10:45
By 1/4 of cabinet do you mean 12U? 500W per 12U is quite strained budget. – Hubert Kario Apr 10 '12 at 11:22
Do you really mean 0.5kw, or 0.5Amps? – tombull89 Apr 10 '12 at 14:26
@tombull89 0.5amps isnt a measure of power. – DD. Apr 10 '12 at 14:45
@DD. I know - however some colocation centers say give a measure in Amps rather than Watts. – tombull89 Apr 10 '12 at 14:50
up vote 5 down vote accepted

You'll never find the exact numbers on a sales website, because it depends entirely on how you configure your server.

What you can find however is the wattage of the installed power supplies. For normal rack servers, the power supplies are 1+1, which means that the power draw will never exceed the total of one power supply (so, 2x 850 watts is still just 850 watts). Blade servers are a different story (as they have 6 power supplies).

For the ubiquitous Dell R710, it has the option of 570w or 870w power supplies (in my region at 240v). 0.5kw is only 500w, so you could really only get one server at peak load before going over your power limit.

We have some R710's though and I can tell you that at 240v with 48Gb of RAM, 2x 6-core Xeons and 4x 15,000 RPM SAS drives they draw no more than about 300w under peak load. That's measured by the UPS and confirmed by the iDrac logs. So you might be able to get two of them under normal load into 500w (this is based on the assumption that your rack provider will simply bill you exorbitant amounts based on excess usage. If you're going to trip a breaker by exceeding your allocated power usage, don't take any risks).

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.5 kW = 500W, not 5000W. – Keith Stokes Apr 10 '12 at 11:01
@KeithStokes Shit, you're quite right. I've been working with UPS's today and I keept thinking of 5 kva... – Mark Henderson Apr 10 '12 at 11:07
"You might be able to get two of them under normal load into 500w" but you shouldn't. The risk you run is losing both servers if they go over that and break their circuit. Not worth it. – sh-beta Apr 10 '12 at 11:34
@sh-beta i dont think the provider will cut the power after exceeding the limit, but charging the power used above the limit. – ercpe Apr 10 '12 at 12:17
@sh-beta Indeed, I have made the assumption that excess power is billed ontop, which is what happens at our colo. If you're in the situation where you might actually trip a breaker, you should always play it safe. – Mark Henderson Apr 10 '12 at 12:29

If you're using Dell servers, have a look at the Dell Energy Smart Solution Advisor (or the Dell Data Center Capacity Planner if its an older server).

Add your server to the solution, edit the configuration to match your server(s), and tell it what sort of workload the server will be undertaking. You will be told the average power draw and heat and sound generation.

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I've just metered some DL360 and DL380 (bought this year) with 16-24GB RAM and full HDD packs. Idle was about 90-120 Watts per server.

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