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I pulled up the datasheet but there's only "Acoustics Sound Power Measured" and I can't make any sense of it. It's got numbers like (page 15):

Power in Watts: >= 300W

Servers/Rack Mount BA: 7.0

I'm trying to figure out if we can realistically install these servers (4) in the closet in our office. Our existing server is installed in there but it's a tower, not a blade. I have essentially no experience with this sort of thing and I'm being asked to help.

jcollum
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    This question appears to be off-topic because it is about a topic best answered by the vendor. – Wesley Jul 18 '14 at 00:20
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    I have a link to the vendor's datasheet. I just don't know how to read it. I thought that was clear. – jcollum Jul 18 '14 at 00:23
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    At a guess: 70 dB(A). A decibel (dB) is 1/10 of a bel (B). The 'A' represents an 'A weighting' (e.g. dB(A) vs dB). 7.0 B(A) * 10dB/B = 70dB(A). (The quantity being measured is likely Sound Power Level - L_WA (that is L with a subscript W, and an added A for the 'A weighting')) – cyberx86 Jul 18 '14 at 01:01
  • @josten Quiet rackmount servers exist. My system racks are pretty quiet. – ewwhite Jul 18 '14 at 14:10
  • I second that. I own **one** quiet 1U rackserver (and two more of that model are ordered). – Hennes Jul 18 '14 at 15:27
  • @josten I have a 4U that's pretty quiet - it uses regular-sized 80mm fans, so they don't have to spin as fast as the tiny ones used in a 1U. – Moshe Katz Jul 24 '14 at 19:41
  • @MosheKatz what's the model? – jcollum Jul 24 '14 at 20:53
  • (Oops, I accidentally pressed '4' when I meant '5'.) [This machine](http://acm01.cs.umd.edu/) is a Poweredge 2900 (Gen III). Right now, it's in [a datacenter](http://www.cs.umd.edu/), but I had it at home for a long time while I was setting it up and it was quieter than the HVAC. – Moshe Katz Jul 24 '14 at 21:19

3 Answers3

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A decibel, dB, is a tenth of a bel, B.

The A on the end is for A weighting, which is a modifier to the noise calculation based on the frequency of the noise, since humans are more sensitive to noise at certain frequencies.

So, that server (apparently constantly at all power levels, which means its fan speed doesn't vary with load) makes 70 decibels of noise, A-weighted.

Shane Madden
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    Somewhere between a typical dishwasher and a washing machine... Not quiet, though not intrusively loud – Chris S Jul 18 '14 at 15:42
  • Where's the 70 from? I only see 7.0 on the datasheet and I can't find "dB" anywhere in the doc (except in the word "standby"). – jcollum Jul 18 '14 at 15:46
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    @jcollum That conversion is not from the datasheet, it's based on the definition of the units they're using. 1 BA is 10 dBA. – Shane Madden Jul 18 '14 at 15:54
  • Ah, OK thanks, figured it was something like that but wanted to clarify. – jcollum Jul 18 '14 at 16:04
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To address the specific concerns about the servers you've purchased...

These will be loud and unpleasant in an office closet. The HP servers I use often for office environments are nearly silent during operation (HP ProLiant DL380p and ML350p) at 22dBA to 25dBA. So 70bBA... not good.

Use a decibel comparison chart:

Passenger car at 65 mph at 25 ft (77 dB); freeway at 50 ft from pavement edge 10 a.m. (76 dB). Living room music (76 dB); radio or TV-audio, vacuum cleaner (70 dB).

or

Quiet rural area (30 dB); Whisper, rustling leaves (20 dB)

But what other options do you have? You are missing a Systems Administrator. Had this person not quit and installed the hardware, and it was found to be too loud, what would you have done then? Are you in a position to return the hardware for more appropriate equipment?

ewwhite
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A lot of server fans speed up if the CPU gets hot, so to some extent this may depend on how hard you are going to work the server, and what temperature the office is.

If the closet has its own cooling there are lots of options for sound insulating it; without its own AC or outside vents then the closet must be vented to the main office.

My experience is that a well built closet with stud wall and a fire door is enough to make other sources of noise in an open plan office of more concern than the servers. I don’t recall ever working somewhere where the noise from the “server room” was more of a problem than people having meetings at their desks, or long phone calls.

As you already have the servers, I would be tempted just to carefully unpack them and power them up to see what they sound like. Sound is very hard to predict, for example just having a carpet in the server closet can be a big difference due to the sound it absorbs.

TessellatingHeckler
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Ian Ringrose
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    @ChrisS, the spec says "All system fans are controlled independent of each other. The fan control system may adjust fan speeds for different fans based on increasing/decreasing temperatures in different thermal zones within the chassis." also see "Quiet Fan Idle Mode" – Ian Ringrose Jul 18 '14 at 16:13