Help me quiet a PIII system

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Zorander
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Help me quiet a PIII system

Post by Zorander » Tue Jun 28, 2005 3:01 am

I have an old PIII system that I would like to quieten for a reasonably low cost. Specs are as follow:

Intel PIII EB 800MHz (Coppermine)
Intel D815EEA motherboard
2x256MB PC133
80GB Seagate Barracuda IV
Samsung Combo drive + Sony CD-ROM
Hercules 3D Prophet FDX 8500LE (flashed with ATI Radeon 8500 BIOS)
M-Audio Revolution
Small ATX case (*)
300W Generic PSU

Current noise source seem to be the PSU and CPU fan. The VGA fan is not audible on top of the current noise (though that may change when the PSU and CPU fans are quitened down). A PSU change looks like a must. Putting the Barracuda IV drive on foam is what I have in mind too.

By "Small ATX case", I am not quite sure what the definition for the case is. It is an ATX case (accepts a full-sized ATX board), but is shorter than normal so that the PSU is directly beside the CPU. There is about 7-10 cm clearance between the PSU and CPU. What are my choices for the CPU heatsink (socket 370)? Can I use a 2-fan PSU (eg. Antec Truepower), passively cool the CPU and directly duct away heat through the PSU's intake fan (considering the close proximity between the PSU & CPU)?

Please help me quiet this system. Thanks in advance!

IsaacKuo
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Post by IsaacKuo » Tue Jun 28, 2005 5:45 am

Sounds like an atx mini-tower case to me. IMHO, this is a perfect configuration for the flipped-PSU fan concept. I have a few systems running with such a flipped fan, so that airflow goes into the PSU from the rear and it blows air at the CPU heatsink. One of these is a mini-atx case (I haven't taken pictures of it for "Single fan madness pt 4" yet).

Basically, your current PSU could be fine, you just need to undervolt the fan to 5 volts. This is a pretty easy modification. First you should strip all 80mm fans from your old equipment to experiment with which one is quietest at 5 volts (note that some 80mm fans won't even spin at 5 volts). Then put the quietest one in the PSU, flipped so it blows air inward.

Does your PSU have a grill in the "bottom" or is it a "straight-thru" airflow configuration? Hopefully, it has a grill in the "bottom". In that case, you'll want to fashion a duct to blow air from the PSU at the CPU heatsink. A modified plastic bottle or cup is good for providing a tapered tube. This will provide airflow through the CPU heatsink, so you can remove the CPU fan.

Note that you do NOT need to have a duct with a perfect "seal". Since you're blowing air at the CPU, the air will remain directional for quite some distance after leaving the duct. In fact, you might not need any duct at all. In contrast, if you try to use the PSU to suck air from the CPU heatsink, you'll need a near perfect "seal".

After doing this modification, you can see what the new loudest components are.

You'll almost certainly want to get rid of the GPU fan. There are a number of fanless GPU cooling options.

Suspending the hard drive is also a good idea.

[Edit:]

To clarify, I'm suggesting that you do NOT replace the CPU heatsink, unless it's really tiny. I've had single fan success with a stock PIII 800mhz socket 370 processor. I removed the fan, and put in a duct. This one wasn't even a very efficient duct setup.
Last edited by IsaacKuo on Tue Jun 28, 2005 6:33 am, edited 2 times in total.

mb2
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Post by mb2 » Tue Jun 28, 2005 5:56 am

heatsink choices are pretty excellent, being as all Socket A heatsinks which work using the clips also work with s370.. so, if u wanted to go crazy, then SI-97 lol.
however, i'd say it was important to keep pricing in perspective; theres no point getting an SI-97 or something when it costs 5x more than the processor.. for example i have cooled my celeron 400 (specced at 23.7W) with 0 fans (not even psu) using a cheapo coolermaster aluminium SoA HS.. some 800mhz p3s are specced as low as 20.8W.. therefore yes u could run just the PSU fan with any half decent HS.
i'd buy anything that was cheap and had a 80mm fan.. u can always 5v it, or take it off if u find it is too noisy still.

as for the PSU, firstly i would try a fan swap, 5/7v-ing or a fanmate on the fan.. checking that it doesn't get too hot.. before shelling out for something like an antec.

MikeC
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Post by MikeC » Tue Jun 28, 2005 8:33 am

I'd just go for the cheapest Seasonic S12 or Super Tornado (rev A3); it's probably under $50 and sure to be much quieter than waht you have now.

NeilBlanchard
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Post by NeilBlanchard » Tue Jun 28, 2005 8:38 am

Hello:

I concur with Mike C. -- but if your case has the PS oriented "sideways", then be sure that the fan has clearance for good air flow. I had an mini-tower IBM Athlon system, and it could not work with a 120mm fanned PS -- I ended up transplanting the innards of this machine into a BQE case, with a Fortron PS.

alleycat
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Post by alleycat » Tue Jun 28, 2005 10:28 am

I've got an 800EB also, and the whole system is cooled by a single low-airflow 80mm fan in the PSU (I replaced the original fan with a quieter one). In my case, the PSU is directly above the CPU HS. The HS is a "cheapo" model, probably a little larger than most in its price range, and with the fan removed. If I were to replace it I would probably choose a fanless Zalman "flower" type heatsink, although I'm happy enough with the temps as they are.

As a first step it might be worthwhile simply removing the CPU HS fan and checking your temps. I doubt you would have any problems at idle. Try loading the system and see what happens. If you're not happy with the temps then you may need to try a different heatsink or a duct. Once you're happy with the cooling potential, you can do a fan or PSU swap.

Zorander
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Post by Zorander » Tue Jun 28, 2005 5:40 pm

IsaacKuo wrote:Basically, your current PSU could be fine, you just need to undervolt the fan to 5 volts. This is a pretty easy modification. First you should strip all 80mm fans from your old equipment to experiment with which one is quietest at 5 volts (note that some 80mm fans won't even spin at 5 volts). Then put the quietest one in the PSU, flipped so it blows air inward.

Does your PSU have a grill in the "bottom" or is it a "straight-thru" airflow configuration? Hopefully, it has a grill in the "bottom"
The PSU is unfortunately a straight-through model. I also checked its innards and noted that the fan connector is obscured by the capacitors and whatever-else on the PCB (I may damage the whole unit in the attempt to remove the cable alone). I'll have to start checking around friends' spare PSU units (if they have any) or hunt for one on the net (how about this or this?). By the way, how can I 5V the fans? Do I have to get a Fanmate or do some cable mods as illustrated by some of the guides available here?

I am also considering replacing the GPU fan to a passive Zalman ZM-NB32J. However the fan is glued to the board and I am not too sure how I can safely remove it. Any tips here? I will also follow the majority's advice to keep the current CPU HSF and passively cool it.

Thanks again!


Edit:
I am in Sydney, Australia. Seasonics don't seem to be easily available here.

Natronomonas
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Post by Natronomonas » Tue Jun 28, 2005 6:18 pm

I recently quietened a very similar setup. The main noise sources were the PSU and HSF, as in your case.

I swapped the HSF for a socketA that I had lying around and attached a 92mm at 5v. This was a great fan, you can't hear it inside the case. I swapped out the PSU fan for a thermally controlled Coolermaster I got at a swap meet for $10 (Melbourne, I don't know if Sydney has similar).

I also put an 80mm@5v on the case exhaust, which stopped the PSU fan from ramping up as much as it was (ie, it stopped ramping up).

It wasn't inaudible, but if it wasn't the middle of the night you had to look for the power LED to see if it was on.

Total cost was the $10 for the fan - the rest you can do with pliers and a screwdriver. Add an extra few dollars for a socket A heatsink if you need one, but you could probably pick one up at a swap meet for very little... or else just put a bigger fan on your existing heatsink (this one had a 40 or 50mm screamer).

Steve_Y
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Post by Steve_Y » Wed Jun 29, 2005 1:27 pm

I'm running a similar system but with a slightly cooler 600Mhz PIII. IMO a system like this is relatively trivial to silence, no expensive specialist components or well thought out air flow ducts are really necessary. The CPU and PSU should be particularly easy. I find that most half decent PSUs can be cooled with a single low noise fan and that CPU should run fine with a passive heat sink.

Mine is cooled by two 92mm Nexus fans (one in the PSU) both running at close to the slowest Fanmate setting (6-7v?). Even in the middle of the night I find them totally silent with the PC's case closed. The CPU simply has a stock Athlon cooler with the fan removed that one of my overclocker friends was throwing away. The PSU fan is fairly close to the CPU, but there's nothing blowing air directly onto it.

Right now it's a pretty hot day, I don't have a thermometer handy but I'm finding it pretty uncomfortable. I've just finished encoding several CDs to MP3 so the CPU has been working quite hard. The CPU temperature is reported as 47C, IMO a perfectly acceptable temperature under load. The system is very stable, I've run the Prime95 torture test for 48 hours without any errors.

I imagine CPU temperature would be significantly lower with a larger heat sink, air flow duct, or slow CPU fan. Any of those should more than make up for the slightly increased temperature of your faster CPU.

Only problem is that you'll probably start to find your hard disk and graphics card a lot more annoying once the CPU and PSU are sorted. They can be a bit more hassle to silence.

Zorander
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How to pry off GPU fan? It seems glued to the core

Post by Zorander » Wed Jun 29, 2005 10:21 pm

Is there any 'safe' (for the card) way to do it? I plan to replace it with a Zalman NB heatsink (I believe it should work out).

On another note, as I previously stated, my case is pretty small and hence not quite efficient with airflow. Nevertheless I will try running the CPU fanless and use a PSU unit that fits the 'suggested requirements' in this thread.

Regards.

Zorander
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Location: Sydney, Australia

Post by Zorander » Mon Jul 04, 2005 8:28 pm

I tried today running the GPU and CPU with the fans off (not removed off-board though) and with case cover open.

Running an old game, Call of Duty, I noticed no artifacts nor system crashes. I then ran ATITool which reported a few graphic corruptions at default speed. However the CPU heatsink was too hot to touch (ouch!). The GPU heatsink was just warm.

Considering this finding, is it really safe to run the CPU fanless (even with a ducting system)? Thanks!

Steve_Y
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Post by Steve_Y » Sun Jul 10, 2005 6:17 pm

If the CPU heatsink is too hot to touch then I don't think you should consider running it like that full time. You need decent airflow over a fanless heatsink, I think putting in a duct and maybe replacing your heatsink with something larger would be a good idea.

alleycat
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Post by alleycat » Mon Jul 11, 2005 12:55 am

I would imagine that leaving the fan on the HS but switched off will have quite a negative impact on the amount of airflow around it. Also, some PIII heatsinks can be too small or have tight fin spacing. If this is the case, you'd be better off with a more efficient heatsink. It shouldn't be difficult to cool your processor using just the PSU airflow.

Zorander
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Post by Zorander » Thu Aug 25, 2005 8:07 pm

Just updating on what I have done (nearly a month ago) with the system.

I replaced the old PSU with another generic PSU sporting a 120mm fan (which I have swapped with a GlacialTech 900rpm fan), replaced the stock PIII HSF with a slightly larger fanless heatsink and turned power off the VGA cooler fan. I decided the Seagate Barracuda IV is quiet enough so I mounted it conventionally. The system is dead quiet now even in the middle of midnight. The fridge 10 metres away is louder and the slight buzzing from my CRT monitor is becoming irritating. :)

All is good now. Long live quiet computing!

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