It's the CPU fan, hurrah!

[ciphergoth]

(geek as always)

After asking "Why is my quiet case so noisy?" on computerhelp, I tried an experiment last night. After running the machine until it got really loud, I opened up the case and put my finger on the CPU fan, stopping it briefly.

The noise stopped completely.

So, I need a new CPU fan that's not so loud. The question is, which fan should I buy?

(read Episode 1 of The Very Noisy Computer including detailed specs)

Comments

[dennyd.livejournal.com]

Big fans are quieter, I'm told. I have no first-hand advice, being largely immune to fan noise... I run my system caseless to keep it cooler, and the noise doesn't bother me.

[grumpy-sysadmin.livejournal.com]

That'd be because big fans don't have to spin as fast to move the same volume of air and, therefore, make less noise.

Or you can run them just as fast and make even more noise.

My spare bedroom requires OSHA-grade hearing protection, so I know.

[skibbley.livejournal.com]

When I worked for a company who made fans, they also said that big fans shift more air per revolution so don't need to run as fast for a given flow rate so are quieter than small fans.

I wonder if architects design new buidlings to take into account heating from computers rather than having air conditioning running in computer rooms while separate heating systems run in others.

[deliberateblank.livejournal.com]

Hmm. The QX-70 looks good for me. Problem is I've seen so much variation on how PC noise levels are reported I really don't believe the specs any more. (This one at 20dB seems to be by far the best cooler on the page - so why don't they make more of it?) It seems like they've decided that noise levels are all subjective, innit, so they may as well lie through their teeth about them.

[selectnone.livejournal.com]

I've happily used the Zalman flower-heatsink cooler, that works well.
You might want to go for one of the new Zalman super-flower coolers.

I'm currently cooled by the Reserator 1, but that won't be suitable if you want to keep everything in-case.

[simm42.livejournal.com]

I have one of the old thermaltake volcano's (the 7 I think)

very good - veriable speed so pretty quiet when its running cool - louder when it needs more.



Is water cooling an option?

Prob about £100 these days for a basic setup (pump, resevoir rad fan and cpu block) and they are pretty easy to install. (www.watercooling.de is probably the best site I know for the stuff)

Out of the ones on that page I would go for the Zalman CNPS7000B-CU Super Flower Cooler AMD and P4 - £32.00


Zalman are very good at cool and quiet and its an all copper block (always go for all copper vs cu/al) the only problem they have is not all motherboards can take them (depends where the capacitors are around the CPU)

[babysimon]

Further thought:

I'm not sure whether replacing the fan will help. You say that the fan is very quiet when first switched on, but it gets louder and the CPU temp. goes up.

In your computerhelp post, gholam suggests the Athlon 64 needs OS support to reduce its voltage and clock rate. On my system the CPU does this automatically (or Linux does it with no configuration?) and this makes a difference - when the machine's been at 100% CPU for a while it's actually quite loud.

I think you need to make the CPU do power-saving when it's not busy; otherwise you'll need to get a very quiet, but also very powerful fan to extract heat you're generating needlessly. My guess is it's not doing this for whatever reason. Investigate ACPI and/or Cool'n'Quiet under Linux?

[babysimon]

Google found this: http://www.fedoraforum.org/forum/archive/index.php/t-23187.html
Relevant?

[ciphergoth.livejournal.com]

I already got powernow-k8 working on my motherboard. It doesn't seem to help. Also, 51 degrees isn't amazingly hot.

My current fan is I think louder than any fan should ever be, under any circumstances. And the Zalman fans are pretty quiet even when going at full whack. So it's probably worth it even if it isn't a total fix - it should bring the system into "can bear to work on it" range...

[babysimon]

Fair enough.

5625 RPM sounds like a lot to me though.

[ciphergoth.livejournal.com]

what would you expect? One problem with the big Zalman fans is that they tend to run at 2000 RPM, which is so slow that some motherboards treat it as "not spinning at all" and start signalling fan failure.

[babysimon]

I can't get lm-sensors to work. If your question is not rhetorical, please reply and I'll reboot and look in the BIOS.

[ciphergoth.livejournal.com]

Me neither, to my great frustration. Yes, please do let me know. Are you using a stock fan then?

[babysimon]

Yep, the pundit one is very quiet at low RPM anyway, and is also specially shaped to fit inside the case. The fans and heatsinks that came with the CPUs went in the bin, though.

[babysimon]

2884 RPM on the desktop machine (another Pundit) after half an hour of playing video. Mind you, temperature at 47C. Hmm.

[selectnone.livejournal.com]

My motherboard has an optional voice-post, and it bitches at me about fan failures when it's turned on.

A fanless PSU and CPU just confuse it, poor thing...

[conflux.livejournal.com]

The standard Zalman flower ones have always worked well for me. They come with thermal paste too and a case mounted bracket to hold the fan over the heatsink. If you are going to get a processor mounted fan then it is also worth making sure the mobo cannot vibrate.

[jhg.livejournal.com]

Science - isn't it great?