Replacing O2 PSU Fan

[CRaven]

Hello,

I'm looking to upgrade my O2 fan to something quieter. I found this old thread mentioning a successful replacement with a Noctua NF-R8-1800 fan:

Nekonomicon - Silencing an O2 using a Noctua NF-R8-1800 as PSU fan

But since that thread is old, that specific Noctua fan is not made anymore, just this one Noctua NF-R8-1800 Redux PWM, but i'm not sure if it's a direct replacement, also I would need to desolder the cables, not a big deal but would void the warranty if I'm not happy with the performance. Any ideas for a similar near silent performance?

 

[Jacques]

I don’t have my O2 anymore but will chip in here. If you’re running a R5K / R7K cpu by all means replace with a quieter fan, you can ignore the PWM wires if you get one of those fans and just connect GND and +12V.

For R10k/R12k I’d get a Papst fan with higher static pressure rating. Also remember the O2’s ram generates a lot of heat and so does the IC just below the CPU card, think it’s the ICE or CRIME chip…can’t remember which one. Yes the R10k/r12k cpus have their own fan but it too needs a supply of somewhat cool air to work with.

With the O2, ALL the heat in the system is being pulled out by one fan, HD heat, ram, cpu, mainboard, psu etc etc. so static pressure has to be considered otherwise its a slow BBQ death for components.

 

[CRaven]

I don’t have my O2 anymore but will chip in here. If you’re running a R5K / R7K cpu by all means replace with a quieter fan, you can ignore the PWM wires if you get one of those fans and just connect GND and +12V.

For R10k/R12k I’d get a Papst fan with higher static pressure rating. Also remember the O2’s ram generates a lot of heat and so does the IC just below the CPU card, think it’s the ICE or CRIME chip…can’t remember which one. Yes the R10k/r12k cpus have their own fan but it too needs a supply of somewhat cool air to work with.

With the O2, ALL the heat in the system is being pulled out by one fan, HD heat, ram, cpu, mainboard, psu etc etc. so static pressure has to be considered otherwise its a slow BBQ death for components.

Thanks! I had some old Noctua NF R8 PWM fans and it did the job. Actually this model has a bit more performance than the Noctua NF-R8-1800. This O2 is indeed a R5000, the installation was quite easy.

Now the only thing making noise is the IBM system disk, which I will replace.

I have another O2 with the R10000, and I have the Papst fan (brand new) , but it's so annoyingly loud

 

[architeuthis]

The Arctic P8 Max might be an interesting option for the beefier O2s: https://www.arctic.de/en/P8-Max/ACFAN00286A

With 5.3 mmH2O the static pressure is higher than that of the original PSU fan (4.8) and with ~ 26 dB it is still less noisy than the original (38.2 dB) and the Pabst (32 dB) fans. Also, the 13 EUR price tag is quite ok IMO.

 

[Jacques]

That’s a nice fan! You could probably undervolt that to 8V-10V and still get very good performance and be much quieter.

I’ll probably pick one up for my G4 Quicksilver powersupply.

 

[CRaven]

Thanks I will try that fan.

 

[instrumental]

I had a similar noise prob with my O2 fan. Couldn't find the exact Noctua mentioned, but I went with the Redux PWM. Works like a charm! Super quiet, but yeah, had to do the cable dance. No warranty issues so far, and it's been a few months.

 

[CRaven]

Good to know, that was the initial plan for me too, but I had a bunch of Noctua NF R8 PWM laying around, so I didn't pull the trigger on the Redux PWM