Silencing my noisy dual MP

[Minotaar]

I've got a dual 1800+ MP system in an antec server chassis (the one with the door). The CPUs are cooled with two Vantec CCK-6035s, and i have four case fans, and a dual fan PSU (Antec 400SL - 92mm on the bottom, 80mm out).

Its too noisy.

First of all the CCK-6035s come with these rediculous fans on them - they whine with a high annoying pitch. Took those out, replaced them with 60->80mm fan adaptors, and put panaflo L1As on them.

Im a little uncomfy with the temperature readout, as I used to be at 35 and 40, and now Im at 50 and 60C. Dont know if this is tolerable, given the (presumed) inaccuracy in the motherboard temp readings. For this reason Im scared about reducing the # of fans to get noise down further. From an empirical perspective, its obvious that fan noise is still the #1 culprit (silencing the HDs and such is not a factor imo right now).

Questions:
1) how can I get an accurate temp reading?

2) Can I afford to further increase case temp by reducing the # of fans (currently 4 + PSU fans)? If I replace them with all L1As will that be bad? Currently they're noname 80 mm fans

3) Should I put the L1As on case duty, and put a more scalable fan on the CPUs?

4) When a fan is "thermistor controlled" what exactly does that mean? Does that mean the motherboard controlls its speed when its plugged into the 3-pin plugs for CPU fans?

My case has two case fans in back, two in front, and the PSU fan. the front is intake, back is exhaust. can I switch this up to improve temps to CPUs? (how do I reverse the PSU?)

5) I've also noticed that the two exhaust fans behind the CPUS are not blowing out hot air, while the PSU is. Sure, heat rises and stuff, but there is an obvious temp difference between the two airstreams. Does this suggest that I can reduce the # of fans?

6) Finally, can I duct from the rear case fans onto the CPUs directly to eliminate the two CPU fans and simultaneously get better cooling? Can these work in "suck" mode, given my current temp settings?

[SpyderCat]

I've got a dual 1800+ MP system in an antec server chassis
.........
Its too noisy.
.........
6) Finally, can I duct from the rear case fans onto the CPUs directly to eliminate the two CPU fans and simultaneously get better cooling? Can these work in "suck" mode, given my current temp settings?

Hi Minotaar,

Although I have a single CPU board, I have a setup as suggested in your #6.
I can't say my CPU-temps have gone down, but the rig is almost silent.
Assuming that you have suitable heatsinks on your CPU's I think you should try this route.
I don't know if your case allows two seperate ducts; this could be a problem.

Ducting will prevent contamination of your case with hot air. --->
#1) Your PSU will get cooler air for cooling itself.
#2) Your CPU-heatsinks will be fed with cooler air, so you need less CFM than in your current setup.

When quiet computing is your most important goal, I think you can get away with just 3 fans.
One fan for each CPU, and a fan in the PSU.

My slightly OC-ed AMD 2400+ runs Folding@Home (=100% CPU load) with a CPU-temp of 57°C.
The CPU is cooled by a 80mm Panaflo L-type at 9 volts.
Case temp is 26°C, exhaust from CPU is 41°C.
Running the Panaflo at 12 volts results in a CPU-temp of 53°C

The Badong-ducts are a bit expensive, but seem to be the easiest way to connect your heatsinks to the extraction fans at the rear.

Regards, Han.

[fmah]

1) how can I get an accurate temp reading?

Try a Compunurse digital thermometer. They have a dual version. Just stick the probe right onto the side of the die right under the heatsink. You'll probably have to remove the heatsink to do it. Use thermal compound to get a good contact.

3) Should I put the L1As on case duty, and put a more scalable fan on the CPUs?

Probably try the next higher speed ones, the M1 which is 50% more CFM, you can always reduce the speed with a controller.

My case has two case fans in back, two in front, and the PSU fan. the front is intake, back is exhaust. can I switch this up to improve temps to CPUs? (how do I reverse the PSU?)

You might test it without the front fans, maybe even remove them to reduce flow blockage. Fans running in series improve the flow, but not as much as fans in parallel. In other words, you'd probably have better result if all 4 fans were blowing out (assuming space for it).

[SometimesWarrior]

Hi Minotaar,

I'm also running a dual-processor machine (two XP1600+ Palominos), with the same case, minus the front door. At first, I had the same HSF's as you, and I agree that they are obscenely noisy (although my CPU temperatures were ~45C on idle, because the case airflow was a mess). I put them on Zalman Fanmates and dropped their voltages to ~7V, but they were still loud. I tried rubber-banding the Antec 80mm case fans on top of them, but the temperatures were going over 65C when I turned the machine off.

Then I bought a couple SK-7 heatsinks and Arctic Silver. After swapping the Vantecs with these Thermalrights, temperatures dropped back down to below 50C with the same 80mm case fans. So I strongly recommend getting better heatsinks.

Then my 1-fan Antec PSU connector burned (due to the Tyan Tiger motherboard drawing too much 5V current... BTW, what motherboard are you using?), and the Antec RMA replacement was the same 400W 2-fan PSU as yours. I immediately took out the 80mm fan, moved the 92mm fan to the outside of the PSU casing, and taped all the extra vents, but the 92mm fan (routed through a Fanmate) still speeds way up, and now my PSU exhaust is hot but the case fan exhausts are practically room-temperature. My CPU's (with 18cfm NMB fans @ 12V) both idle at <45C, but the system is no longer quiet.

Following powergyoza's article will really put you on the right track. I would (in fact, I'm going to do this myself soon) remove the 92mm fan from the PSU, put a quiet 80mm back in, tape up the bottom hole, and duct the PSU. I did this with my first, 1-fan PSU, and it worked wonders.

So to summarize: you don't need faster CPU fans, you just need better heatsinks. Powergyoza's 6V L1A's (see his article) worked just fine as heatsink fans. Also, you will definitely need case exhaust fans; the PSU by itself will not be able to handle the enormous amount of heat generated by two (presumably Palomino-core?) MP1800+'s, once you've quieted it with a slower fan.

Also, you can likely remove the front intakes; as long as there is ample ventilation in front (and no other source of air--I suggest taping up any extraneous case holes), the air will come in from the front anyway. Try it, and I think you'll see the system temperatures do not change much.

As for CPU ducting: I plan to try this out in a few weeks, after finals. I have a hunch it will work wonders, unless your case airflow is already highly-optimized. I wonder if powergyoza's tried it...

[Minotaar]

Yeah I had the Tiger amperage problem too. i sent it back and they replaced it. I wont discuss the *****ing stuff here, but it makes me very angry. They fixed the board and gave it to me, with a PSU connector that had an extra MOLEX connection for a 5V plug. I hope that fixes it.

I read through the PSU ducting mod and powergyoza's article, and I have to say that I think your suggestion of larger heatsinks sounds best.

Perhaps you can explain it to me better, but I dont see why ducting the PSU is an advantage. The internal components should be less sensitive to heat than the CPUs are, especially since the PSU is supposed to be the ATX air exhaust, and thus getting the hottest air.

Have you ever used a Badong duct? is there a way to fit them in the fan clips in the antec cases?

[SometimesWarrior]

Perhaps you can explain it to me better, but I dont see why ducting the PSU is an advantage. The internal components should be less sensitive to heat than the CPUs are, especially since the PSU is supposed to be the ATX air exhaust, and thus getting the hottest air.

Well, some guy did a fanless PSU mod here, and he said temps on key components were up in the 80C range, which was well within their (very high) tolerances. But the thing still failed after a few months, perhaps because a few other components were sitting in hot pockets of air, or something. Also, MikeC has mentioned that the no-name PSU's that he mods with slow fans typically last less than a year before they go haywire. And, all the "quiet" PSU's with thermally-controlled fans aren't nearly as quiet if the PSU is heated up with lots of CPU exhaust, because they spin their fans quickly to get rid of the excess heat.

In short: I only duct my PSU because I've been told to, not for any technical reason.

Have you ever used a Badong duct? is there a way to fit them in the fan clips in the antec cases?

Sorry, I don't have any experience with the Badong (or any other) duct.

[powergyoza]

Im a little uncomfy with the temperature readout, as I used to be at 35 and 40, and now Im at 50 and 60C. Dont know if this is tolerable, given the (presumed) inaccuracy in the motherboard temp readings.

Can't add much to what you guys have already mentioned, but FYI, your temps are fine for that motherboard.

[MikeC]

4) When a fan is "thermistor controlled" what exactly does that mean? Does that mean the motherboard controlls its speed when its plugged into the 3-pin plugs for CPU fans?

It means there is a heat sensitive resistor connected (usually) to a heatsink or other hot part in the PSU which is in the fan voltage circuit. When the thermistor (thermal resistor) gets hot, its resistance goes down, and the voltage to the fan is raised. Each thermistor controlled fan PSU tends to have its own unique behavior; some are much more conservative, making the fan speed up to full blast almost at idle temp; others are more noise-conscious, speeding up the fan only beyond a fairly high temp point but (ideally) ramping up to high voltage when really needed.

[fractal]

I've got a dual 1800+ MP system in an antec server chassis (the one with the door). The CPUs are cooled with two Vantec CCK-6035s, and i have four case fans, and a dual fan PSU (Antec 400SL - 92mm on the bottom, 80mm out).

Its too noisy.

First of all the CCK-6035s come with these rediculous fans on them - they whine with a high annoying pitch. Took those out, replaced them with 60->80mm fan adaptors, and put panaflo L1As on them.

I have a tyan tiger mp dual athlon system in an antec case. I am using the antec sx830 myself but the design is similar. I have a pair of svc cg68 heat sinks using the fans that came with the heat sink. I could drop the noise a couple dba by switching to panaflows but ... well ... haven't. I have absolutely no problems with either noise or cooling. The single fan stock 300w power supply is clearly the loudest component in the system. The 28 dBA, 34 cfm 80mm fans that come on the 5 dollar heat sink are certainly louder than 21 dBA, 24 cfm panaflows on the back of the case but are a little quieter than what came with the power supply.

You did good by deciding to use an 80mm fan. I think your mistake was in trying to retain your old heat sink. You paid more for your adaptor ring than you would have paid for a cg68 that comes complete with a fan and a dab of goo (which works as good if not better than AS for most users imnsho, but that's another rant).

Certainly a 33.95(+ cost of fan) slk800a will do a better job than the 4.99 cg68, but will they fit on a tyan tiger mp?

[Minotaar]

Well, 10 dollars isnt too much to pay to reduce noise. I paid 5 dollars a piece for the fan adaptors at cusa. I've never seen that kind of heatsink that you mention; what sorts of temps are you getting? and how fast are your CPUs?

The heatsinks you have appear to be 80mm wide all teh way across - is that true?

My power supply doesnt seem to be responsible for that much of the noise. I havent removed the front fans yet, but Im doign that first.

Im sort of ticked that the CCK-6035s are so bad. I paid good money for those suckers a year and a half ago.

Is there a good way to mount a large large fan in the back instead of those two 80mm ones? I wish I could put a 120mm sucker back there

[SometimesWarrior]

Im sort of ticked that the CCK-6035s are so bad. I paid good money for those suckers a year and a half ago.

Yeah, I was ticked off too, when I saw my temps drop after upgrading my heatsinks. One of them I put on my roommate's K6-700, to replace the FOP32 aluminum cooler and its failing fan, and 5-volted the new fan. The other I put on my videocard.