Modifying an O2 to run silently

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po6labs
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Modifying an O2 to run silently

Post by po6labs » Wed Aug 01, 2018 10:52 am

Would you think that it could be possible to modify an O2 so that I runs silently?

The fan is really loud for today's conditions and I wonder if there would be any options to make it run silently. Maybe with a modern fan replacement or some other cooling system. Did anyone every try something like that?

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Raion-Fox
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Re: Modifying an O2 to run silently

Post by Raion-Fox » Wed Aug 01, 2018 11:37 am

People have replaced the fans but you absolutely need to find one with similar CFM and static pressure.
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GRudolf94
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Re: Modifying an O2 to run silently

Post by GRudolf94 » Wed Aug 01, 2018 1:43 pm

Start by getting the OEM fan's datasheet, browsing thru the Noctua catalog and trying to match specs. As bossman said above, volume (cfm) is not the only thing that matters, the fan has to be able to push that volume of air thru the O2's cramped innards. Hence the need for a quality fan. The closer the impeller edges are to the frame, the better pressure a fan will be able to develop. Cheaper fans use cheaper plastic, where impeller creep would make the blades deform and extend, crashing into the frame, so they make these fans with a bigger gap at the perimeter of the impeller.
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JacquesT
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Re: Modifying an O2 to run silently

Post by JacquesT » Thu Aug 02, 2018 1:25 am

I'm testing a Coolermaster Blademaster 80 in my O2 atm. 40cfm @ 3000rpm with 4.23mmH2O rated. So far so good, it does have a slightly annoying wave frequency hum though.
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:O2: 300Mhz R5200, 384Mb, 6.5.22m, FPA with :1600SW: [300Mhz R12k project in the works]

po6labs
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Re: Modifying an O2 to run silently

Post by po6labs » Thu Aug 02, 2018 4:32 am

Cool, thanks for the input guys. I've just contacted Ian of http://www.sgidepot.co.uk/sgi.html as he offers some modified PSUs right off the bat. That might be the easiest option. I'll let you know about the progress of this endeavor.

Maybe also adding an SSD drive would be great. Did anyone do that?

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gijoe77
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Re: Modifying an O2 to run silently

Post by gijoe77 » Thu Aug 02, 2018 7:11 am

po6labs wrote:
Thu Aug 02, 2018 4:32 am
Cool, thanks for the input guys. I've just contacted Ian of http://www.sgidepot.co.uk/sgi.html as he offers some modified PSUs right off the bat. That might be the easiest option. I'll let you know about the progress of this endeavor.

Maybe also adding an SSD drive would be great. Did anyone do that?
I have a SSD in my o2, the problem is the SCSI-to-SATA adapter has spiked in price like crazy recently, I don't know why but I guess there is one person with all the adapters and they are trying to corner the market...

for example currently at $2k, I bought mine for $250
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Trippynet
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Re: Modifying an O2 to run silently

Post by Trippynet » Thu Aug 02, 2018 12:31 pm

There's a Noctua fan which is a common mod for the O2. I fitted one to the PSU in mine and it made a huge difference. It doesn't move quite as much air, so it's better for the R5000/R5200/R7000 O2s, not sure how well it copes with the hotter R10k/R12k ones.

HDD wise, an SSD is best for noise (obviously), but they're not cheap to fit these days. However, there are SCA drives out there that are MUCH quieter than anything available at the time of the O2's release. With a quiet HDD and a Noctua fan, my O2 only makes as much noise as a modern PC.
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po6labs
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Re: Modifying an O2 to run silently

Post by po6labs » Thu Aug 02, 2018 4:45 pm

Sounds good, thanks. I've got an R5k and I'll try with a new fan and a as-silent-as-possible spinning drive before I'll go the SSD route.

Trippynet: do you happen to know the model name of that Noctua fan?

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Re: Modifying an O2 to run silently

Post by JacquesT » Thu Aug 02, 2018 4:56 pm

Noctua NF-A8 FLX or NF-A8 PWM are the highest rated Noctua at 80mm at 2000 (1.96mmH2O) and 2200 (2.37mmH2O) respectively.

The other popular fan is the EBM Papst 8412N fan, spins at ~3100 rpm, has a static pressure rating of about 4mmH2o but is noisier at 32dB(A).
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Trippynet
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Re: Modifying an O2 to run silently

Post by Trippynet » Thu Aug 02, 2018 5:04 pm

I used the NF-R8 in mine. But as I say, mine is only a 200MHz R5000, so a lot depends on what CPU you have. This Noctua fan is almost silent, but moves a bit less air.

Edit: If you've been in touch with Ian, enquire about drives. He's tested pretty much every one out there and can sell you a very quiet one.
:Indigo2_IMP: R10000 195MHz, 384MB RAM, SolidIMPACT, 36GB 15k & 300GB 10k drives, new/quiet fans, IRIX 6.5.22
:Fuelb: R14000 600MHz, 4GB RAM, V10 Graphics, 72GB 15k & 300GB 10k drives, new/quiet fans, IRIX 6.5.30
:O2: in storage...

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