Seeking recommendations for 900+ W quiet PSU

PSUs: The source of DC power for all components in the PC & often a big noise source.

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Seeking recommendations for 900+ W quiet PSU

Post by Shaping » Tue Jun 30, 2009 9:15 pm

Hi everyone.

I need some assistance selecting a very rugged MM 4U rackmount case and quiet PSU (900+ W).

I currently own a custom Akiwa GHI-691. This is a lovely 6U case, and I enjoy every aspect of it except the noise. The installed Zippy M1W4-6D50P 1U 1300 W "3+1" PSU radiates at 42 to 45 dB, and has been slowly killing me for the last six months (I work in a master bedroom--math, programming, video, sound--I need quiet).

Following is the gear in the box, plus a few extra items (like the Blu-Ray burner and Solid Data SSDs) that I need to put in the new MM 4U:

1 ASUS DSEB-DG/SAS (12" x 13") motherboard
2 x Xeon 5482 CPUs
8 x 2 GB Kinston 800 MHz FB-DIMMs
8 x 1 TB WD SATA 2 HDDs (eventually all SSDs)
4 internal 256 GB SSD drives (Solid Data)
1 5.25" Blu-Ray burners (if 4U)
1 Floppy/card reader
1 Areca 1680ix-24 RAID card
1 FirePro 8700
1 Claro Halo sound card
2 USB ports
1 mouse
1 keyboard

This needs about 700 W or so. I may add another FirePro 8700, which will bring the Power well over 900.

I see that the Seasonic M12D-850W ([link deleted]) is the current favorite high-power quiet PSU. I had my heart set on a PPC Silencer 910. Why is this not in the SPCR list? Is it much noisier? I do not need modular connectors, and James (lead engineer at PPC) says they don't like to use the modular connectors because they've seen problems with oxide and voltage drops. These are gold connectors usually, aren't they? Can anyone confirm this?

My top choices for the 4U rackmount case are


[link deleted]


[link deleted]

These boxes take 3.5" hot-swaps. Ideally I would like a MM 4U box (which is the smallest size that can handle a PS2-form PSU [without a special bracket]) that has 16 or more 2.5" hot-swaps, plus room for 1 or 2 5.25" devices and a floppy/card reader. Only Supermicro gets close, but I don't like the Supermicro look (they write their name all over their cases in big tacky letters). The time may be too early to move to the 2.5" format, in anticipation of phasing over to all SSDs, but I like the idea. Thoughts? Are we certain that forthcoming SSDs will hold to the 2.5" form-factor?

I am open to suggestions. I want the box to be very quiet this time, but, because my power requirements are very high, I am willing to allow more noise than many of you. I think 28 to 30 dB is probably my top end. Not sure. I've noticed that a flatter spectrum is much easier to tolerate. The one coming from the fans in the big Zippy has a clear center-frequency and this grates on me.

Also, I really want to mod the GHI-691 to make it acceptably quiet. I have searched everywhere for quiet 38 mm x 28 mm 12 VDC fans with a 10 or so CFM and a descent static presssure (5+ mm Hg), but can only find a 37 dB (still noisy) candidate from Mechantronics, who must sell me 1000 of them when I want eight. Any suggestions are welcome here too.

And I've asked the guys at Tri-Mag how difficult it would be to tear-out the metal ceiling between the 1U PSU bay (bottom) and 1U rear-mount backplane (middle), which is just under the card-cage (top), and they said they would make a mess of the box, and that buying a new case would be much cheaper. The GHI-691 with the Zippy PSU costs around $2000. It goes onto Craig's List, if I cannot discover an affordable way to make it quiet.

Thank you.


Last edited by Shaping on Wed Jul 01, 2009 10:18 pm, edited 2 times in total.

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Post by SebRad » Wed Jul 01, 2009 3:10 am

Hi, I think that Zalman 1000w PSU is still the quietest PSU SPCR has tested at high outputs. There is also a recomended PSUs section and the some PSU reviews have tables with output vs noise for several PSUs.
Be aware the Zalman PSU is quite long, longer than std ATX format so check your case has room for it if you go that route.
I think your power requirements are over-estimated, as far as I can work out your Xeons are equivilent of Q9750, 45nm quad core chip. Anandtech tested overclocking on QX9650 and had it at 66w at 3.2GHz.
Allowing 100w per CPU, 50w for motherboard and RAM, 100w for the HDDs and 150w for the video card brings us to "only" 500w and I think that's over estimated. Can you borrow, buy, steal a power meter to find the "real" current power draw of your system?
SPCR recomended PSUs
Good luck, Seb
i7 2600k under NH-C14 w/2xTY-147PWM fans, P8P67Deluxe, 8GB RAM, GTX560Ti OC w/TwinTurbo II and BIOS fanspeed mod. MX100 512GB & 2TB EARX in Scythe QuietDrive outside case. Antec Signature 650 fan swapped. CoolerMaster 201C with 2x92 + lower 92mm fan out rear, holes-in-floor and mesh top+front intakes.

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Post by Shaping » Wed Jul 01, 2009 3:54 pm

The power is not likely overestimated. The CPUs are spec-ed at 150 W each. I do not see them getting this hot most of the time, but prefer to calculate based on the ceiling. The 16 GB of FB-DIMM is extremely hot, close to 100 W, if not slightly more. The FirePro 8700 is rated at 225 W and at peak load is hot enough to burn flesh. The best online power calculator I could find shows around 670 W. Orbit Micro, who are working on a case for me, calculate a similar figure--around 700 W.

I would like to measure the power. Can anyone recommend a high-quality power meter?

Why is the PPC Silencer 910 not well liked and listed among the recommendations? Is the problem noise or not having modular connectors?

Last edited by Shaping on Wed Jul 01, 2009 10:34 pm, edited 1 time in total.

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Post by fyleow » Wed Jul 01, 2009 4:00 pm

The FirePro 8700 is the professional version of the 4870. The 4870 pulls about 130 watts at full load. 225 watts is a bit of a conservative figure.

You can use a Kill A Watt power meter to check your PSU's actual power draw.

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Post by Shaping » Wed Jul 08, 2009 9:57 pm

I used a THP103 AmWatt Appliance Load Tester to measure power dissipated into the four power cables feeding the 4 PSUs in the Zippy. The total was about 515 W. With the Unigine Tropics demo running with all parameters maxed (CPUs between 65% and 75%, power rose to a total of 615 W. If I put in another FirePro 8700, power consumption would rise to about 715 W.

I am trying to rationalize using a 2U rackmount because their front panels are more ergonomic than the available 4Us, but I cannot find a quiet 700 W 2U PSU. So I am giving up on this idea.

A 4U is still the best choice for low noise and high-compute density.


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