Loud Fans

[normabkrchk]

I have a PC here that sounds like a small jet taking off (well, not that bad, but it is pretty loud) When I remove the side cover in about 20 seconds I hear a soft click and then the fan quiets down. I'm not sure which fan though is the issue - Power Supply or CPU. This is a P4 3ghz machine with an Enlight power supply, those are the only fans in the case. Any suggestions?

 

[sailer]

Can't say for sure, but it sounds like the fan speed is linked to the temp readings. When you open the case, the temp goes down and the fan speed lowers and is noticably quieter. You need more fans, probably a couple blowing out the back of the case and one blowing into the case. Probably one blowing out the top would be helpful as well.

On the surface, it might seem that the extra fans would be even louder, but if they are linked to temp readings, they will end up going slower, and therefore be quieter. Another thing is that if the heat is lowered in the case, the components will last longer.

 

[Doughbuy]

I'm not sure about the click, but if your fans are connected via your mobo, your mobo would supply power depending on temperature levels. If you take the side panel off, the temp would go down, thus making the fans revolve slower... specs and a description of case airflow would help here.

 

[normabkrchk]

This is an tower PC with Intel D865GBF MB, P4 3.0Ghz, 512mg DDR Ram, W2K.

I installed Intel Active Monitor and the problem doesn't seem to be temperature driven. I took the following three readings over a 2 hr period.
Processor Zone Temp 51 50 49
System Zone 1 Temp 37 36 36
System Zone 2 Temp 40 39 39
Processor Fan Speed 4753 5197 5187
System Fan Speed 2607 2603 2592

The first set is with the side cover slighly off, the last two are when cover is on. Looks to be the Processor Fan is the culprit as that's the only number that's changing significantly. The system is clean inside and outside, sits about 5" away from a cabinent on the side cover side, about 10'' in the back, open on the other side so airflow shouldn't be a problem.

 

[TkdRO]

Sounds like its your case fans that are really loud. Get some better ones.

Change your case fans to Zalman ZM-F1 for 80mm and if you have a 120mm fan change those to the F3. they come with Quiet mode feature.

 

[normabkrchk]

There is only one small case fan, bottom front that pulls air into the PC; it's quiet. First I'm going to cut a hole in the side cover, then may add an exhaust fan to the back. It is definitely the CPU fan that's noisy.

 

[Pain]

You can verify that by opening the case and simply placing your finger on the cpu fan to slow it down. If it's gets quiet, there's your answer.

I'd be more inclinded to find out what is actually controlling the cpu fan speed instead of just cutting holes in my case before I understood the reason.

 

[normabkrchk]

Side cover on - CPU Fan Speed goes up, gets loud, temp goes down slightly.
Side cover ajar - CPU Fan Speed goes down, gets quieter, temp goes up slightly.

Besides temperature, what would control CPU fan speed?

 

[Pain]

What I mean is, how is the fan being controlled? Do you know? If it's being controlled in the bios and the cpu temp is within normal range, just increase the fan control setting a few degrees and then maybe look at improving airflow in your case without cutting a whole in the side. That's sort of like cutting off your finger because you had a splinter.

 

[TkdRO]

If you sure its your CPU fan, just get a new CPU fan, i think its a lot better then cutting a whole in the side of your pc, which may not even fix the problem.

I would go with any of the Zalman Heatsinks, they are very quiet and efficient coolers. and NO i don't work for Zalman, i just like their cooling products.

 

[normabkrchk]

Thanks for all the advice - learned a lot from the replies. The problem is fixed, too! And without cutting the cover. I added a fan to the back to pull air out of the box. Wow, what a difference - can't even hear the PC running - temps are the same, but the Processor fan is running at half - about 2400 rpm.

Again, thanks!