The curse of 1u chassis: loud 40mm fans!

thisnewaccount

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Oct 20, 2018
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i recently laid my hands on a working but empty 1u chassis that was being disposed of (a supermicro sc813m), to hold the last few drives i can add to my "backup" server. hey, can't beat *free*, right? anyway, bought a used power board off ebay (a supermicro JBPWR2) along with an SFF-8088 to 8087 bracket, fished out a breakout cable and a fan splitter out of stash of parts, assembled the beast... tested it in a large room -- hey, not too noisy... and racked it.

when i turned it on again, what the...?!? it's noisier than my 2u jbod drive array! (that quantum dxi6500 i posted about some time ago)

i quickly found out the 40mm fans (FAN-0061L4) are rated at 44db each, so 4 times that... either i get quieter fans or i put some in-line resistors that came with noctua 120mm fans i bought for my 4u boxes (norco 4224 & rosewill 'l4500). For the fans, i know the FAN-0100L4 would fit, though it appears to be costly to purchase in canada and only drops the noise level 10db. another fan that could be an option (Sunon 40x40x20mm 3 pin fan #KDE1204PKVX, https://www.amazon.ca/Sunon-40x40x20mm-pin-fan-KDE1204PKVX/dp/B006ODM76C), as it is cheaper & *much* quieter, though not sure it could really be used with a at supermicro 1u chassis like mine (20mm deep instead of 28mm, 10.x CFM instead of 16.3).

at the moment, am leaning towards using the resistors (cheapest known solution), but i have to make sure it's safe to do so.

or is there another option i'm missing?

thanks in advance!
 

PigLover

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Jan 26, 2011
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Those are pwm fans. Slow them down with motherboard controls. While a 1u chassis will never run ‘quiet’, they are really tolerable when running at 50% or less.

The problem you will have by replacing them is that the replacements will likely not have the static pressure characteristics required to move air in the chassis. Consumer fans (even good ones like Noctua, etc.) definitely will not. And the Sunon you reference will not be quieter than the ones you have once you slow them down.
 

thisnewaccount

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Oct 20, 2018
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there is no motherboard in the chassis, only a JBPWR2 board that lets me turn the beast on/off with the power button on the front.
it's just a dumb jbod chassis.

as for the sunon replacement i mentioned, i would not slow it down, as 27db is much better than the 44db i currently have (values per fan).

are you saying even the replacement FAN-0100L4 would not have the static pressure necessary to push air through the chassis? i would understand that with, say, a noctua fan, but the supermicro-branded stuff (or even the sunon)?
 

PigLover

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Jan 26, 2011
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If all you are cooling are the drives those fans should be fine.

Alternatively, you could look on ebay to replace the JBPWR2 board with a JBPWR3, which will give you IPMI-based PWM control of the fans. Depending on what is on the market at the time it might be cheaper than replacing the fans.
 

thisnewaccount

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Oct 20, 2018
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Heavens. the CSE-PTJBOD-CB3 (what you called 'JBPWR3') is more expensive and difficult to get north of the border, so much so that the fans were cheaper (esp. the sunon i mentioned) every time i looked.

that's why i'm looking at the sunon (KDE1204PKVX): 4*16.32cad vs. 150-200cad for the better power board.

that ~10.x (*4) cfm should do it if it's just hard drives (thanks for confirming that), but am still unsure how it would fit, if the "missing" 8 mm could torpedo my plans. to kind of repeat my question, did anyone lurking around sth use these fans with a chassis like mine?
 
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