Next Step in Quieting Computer?

[dblevitan]

OK, I've been working on making my computer as quiet as possible. I'm running a P3 750 (OC'ed to 879). Right now I have an Antec Performance Plus 660B case. I have a total of 4 fans (outside of the PS. 3 are silencers (80 mm - 20 dBA) - one of which is on the CPU (SK-6 HS), one on the side blowing in, one in back blowing out. I also have a 40mm Adda 19 dBA fan on my Radeon AIW. The only other moving part I have is a Seagate 80 GB Barracuda IV. Now it has become really quiet, but when there's no backround noise, it still seems loud.
Right now my case temp is 26 (outside temp is 23). CPU is 30 without load, 40 or so with load, If I disable all the case fans (except CPU and video), case fans go to around 30, CPU stays the same.
What's my next step? Will rubber grommets on the side fan help? What about the SilentDrive from QuietPC? Right now I think that the hard drive and silencers are making the most noise.
One thing I'm thinking about is getting a duct from the top of the CPU heatsink to the side air hole, and sucking air out. This would remove the source of most of the heat in the case, and the fans in the PS could deal with the heat from the drive and the video card. Is this possible and how much would something like this cost?
Thank you,
David Levitan

 

[SuperPickle]

I've read places that say the SilentDrive used with a 7200rpm or higher drive is not recommended due to heat. It'd be a shame to burn up the drive just for a dB or two. If you're handy, this tip might work nice (it did for me). In my experience, rubber grommets don't do much for dampening vibration; you may find better results with some sort of heavy case dampening like a rubber mat on the side of the case. Also, a large passive HS on your Radeon will eliminate one fan. I used stock PII HS with no fan for my Radeon and I could still OC it.

Changing your SK-6 fan from blow to suck and then ducting it right out the back of the case will eliminate yet another fan...making the CPU fan a dual-purpose exhaust as well. Cheap-as* plastic flex ducting for clothes dryers would do the trick. If you choose this route, i suggest skirting your SK-6 on the top so it sucks air from the lowest part of the HS giving you the best cooling.

Lastly, although Antec PSU's are quiet, replacing its exhaust fan with a hush-hush fan, might shave a bit more noise.

 

[dblevitan]

Yeah, the SilentDrive doesn't sound too great when used with a Seagate (which gets hot in general). I'll look into the sandwich trick to maybe implement that.
I actually wanted to put a large heatsink on the radeon - only problem is that you lose one PCI slot and that the modification is permanent. If it doesn't work well - there's not way to change it. So I'm not sure I want to go with this route.
I do want to make a duct - my only problem is finding a flexible pipe that will go from 60mm on one side to 80 on the other. If it is not perfect, the fan efficiency will be decreased. Any idea on getting some type of material for this?
-David

 

[Auric]

Radeon does not require a heatsink so tall as to block a slot. However, for better cooling you do not want to use that slot anyway. If you use a tidgy bit of Insane Glue (TM) at the corners it will not be permanent, as opposed to an epoxy thermal compound mix.

For flexiable ducting hit Home Depot or the like.

 

[dblevitan]

So by using something like superglue at the corners and thermal paste, I should get good cooling results, right?
I was thinking of using the Zalman heatsink. I don't mind losing that PCI slot that much -5 is enough at the moment.
Finally, the fans in the antec trupower PSU, are they themselves thermally controlled, or doesthe PSU control them?
Thanks,
David Levitan

 

[tallest1]

Quick question: what do you think of the Seagate 80GB? I'm seriously thinking of replacing my two harddrives with one.

 

[hmsrolst]

I would get a fanbus (pcmods is good) and undervolt the Silencers some. I did that in one of my systems that's very similar to yours (SX600 with 3 Silencers--one in back, two in the front) and it definitely reduces the noise. You'll add a couple of degrees on your case temps, but not as much as turning off the case fans. You can also easily run them at full speed if you have a situation where you're more worried about heat.

 

[mcvan]

If the case fans don't change the CPU temp, why bother with them at all? The PSU fan is guaranteed to produce some airflow anyway.

One of my systems is a P3 - 550 (slot) oc'd to 733 via FSB, lowered VCore (1.45V), GlobalWin VOS32 heatsink w/o fan, generic PSU w/ fan @ 4V, one back panel Panaflo 80mm fan @ 4V, Seagate Barracuda IV 40G HD in elastic suspension mount, generic 18" ATX case, well damped w/ highest density carpet underlay foam. This system is only audible in the wee hours of the morning when ambient noise drops to tomb levels. It makes about as much noise as a single Panaflo 80mm fan running unobstructed at 5 volts.

The elastic suspension for the drive is an alternative to my original aluminum sandwich idea (yeah, I wrote that overclockers piece a while back...) This probably works better for already-quiet drives.

I've also got a P4 system that's almost as quiet as the P3 above: http://www.silentpcreview.com/goto.php?t=s&id=14&a=1

 

[dblevitan]

Very nice site.

Well, I dropped the silencers, and let the PSU control the fan on the radeon. That dropped noise levels, but also increased temps. Right now, after running prime95 for maybe 1 hour at 879 MHz, I'm getting CPU temp of 45 and case temp of 31. Not too bad I think.

I looked at the PSU fans (made by Dynaeon), and they appear to be ~40 CFM fans running at 34 dBA. Of course, they are undervolted by the PSU, so they are running a lot slower (anybody have dBA specs on the TruPower PSUs?). Because they will probably end up being the only fans (besides the CPU fan) in the system, is it risky to replace them with lower CFM fans? Also, does anyone know whether the fans are thermally controlled by the PSU or are they individually controlled? From the model numbers, I think they may be individually thermally controlled. Is there anyway to change a regular fan into one that is automatically controlled by temperature?
In terms of fans, I would probably use a silencer 80 mm and a Vantec Stealth 92mm. both are 20 dBA, and are 27 and 28 CFM, respectively. I could also get a 23 dBA 92 mm Papst that goes to 27 CFM, but there is no corresponding 80 mm fan at that CFM and dBA.

I'll drop by home depot tomorrow and see if there is anything adequate there for a duct to go from the CPU to the outside of the case. I might also cut out the grille on the back of the case and replace it with a simple grille (like on the PSU).

Also, what is the best material to dampen cases?

In answer to the question about the Seagate - it is very quiet. A lot quieter than my old Maxtor drives. The reviews and specs don't lie, it probably is the quietest drive around.

Thanks,
David Levitan

 

[dblevitan]

One thing I'm noticing is that after I shut off prime95, CPU temps have gone down to 35, but case temps are at 31. So I do need to increase case circulation. The duct should take care of this, but until then, I turned a silencer in the back on.
-David

 

[mcvan]

31C is nothing to be worried about -- I'll bet there's not a single component in your case not rated to run fine up to ~50C or higher.

The Vantec fan is considerably louder than the Silencer, numbers don't always tell the truth. The most consistent way to predict noise without actually hearing a fan is to look at the AMP rating. If a 12V fan has a current rating under ~0.13A, it will be pretty quiet, Under 0.1 AMP, it can be silent when undervolted to ~7V. Anything over about 0.15AMP -- forget it. It's going to HUM at too loudly at virtually any speed. It just has to do with the power / mass / coils of the motor. The Silencers, IMHO, are among the quietest fans you can find. period. At 7V & less, they're essentially inaudible inside a case.

Most PSU fans are rated 0.2 to 0.3A. Even with 4.5V, they hum enough that it is not possible to obtain an inaudible system. My solution is to replace the PSU fan with really quiet 80mm fans rated at ~20 dB or less, then set it up vith a voltage controller or 5V/12V switch. I keep the fan at min voltage normally, which makes the PC inaudible under a desk. If you get hot weather or an urge to play doom (or whathaveyou) for 6 hrs straight, turn the fan up, get a bit more noise, but much better cooling. (The PSU fan speed can make 3-5C difference in CPU temp, because of its effect on case airflow.)

 

[dblevitan]

True, the temp doesn't sound like a problem, but I'm running a silencer in the back which is hooked up to the truepower fan connectors - can't hear it at all. The Adda fan on the radeon also can't be heard when connected to the truepower connectors. I'll probably just undervolt the adda fan since it provides adequate cooling for the radeon and is inaudible. The only problem with the silencer is that it doesn't start at 5V or whatever the PSU supplies it. I'll have to figure out a way around that.
I will replace the fans in the PSU, but my question right now is whether the two fans need to have the same CFM? If not, I can get a 92 mm papst 23 dBA rated at 36 CFM and an 80 mm Silencer rated at 27 CFM. Otherwise I'll find two fans with the same CFM running at 20 dBA or less.
-David

 

[mcvan]

The Antec PSU is a 2-fan design? Just remove the 2nd fan. It will hardly change PSU temps at all. Check out these PSU articles --


<FONT color=#0000ff>http://www.silentpcreview.com/goto.php?t=s&id=9&a=1</FONT>
<FONT color=#0000ff>http://www.silentpcreview.com/goto.php?t=s&id=15&a=1</FONT>

 

[tracerbullet]

I guess it's been said, but - I started off with stepping down from 4 case fans to two, with no difference in temps. Then replaced the 2 rears with Panaflos, much quieter and still same temps. Did the power supply fan, same thing - more quieting and no temp increases. Lastly hit the CPU with a Thermalright SK7 and a variable speed YS Tech fan. For gaming I turn the fan on the CPU up, for the internet I keep it down. Even at the "no noise" setting of the CPU fan, with that amazing new heatsink I have lower temps on the CPU than ever.

I guess I'm saying if I had your PC, I'd 1) Replace the P/S fan with one of the same low-noise fans you put in the case. 2) Think about a variable speed CPU fan to get even less noise there in low demand situations. 3) This is my next step - invest in some sound dampening materials - Dynamat or equivalent in a few spots of the case, and also some sort of acoustic absorbing foam to catch some of the noise bouncing around inside the case.

 

[mcvan]

Dynamat is basically a panel dampener. It reduces the resonance of whatever panel you apply it on. That helps to ensure the panel doesn't vibrate and make noise when excited by other vibrating things such as hard drives, fans, etc. It does little to absorb sound or stop transmission of sound. As you probably know Dynamat was developed for use in cars -- you can see how the large body panels in cars would benefit from such treatment, but in PCs, it's really not much of an issue, especially if your fans are already running at low voltage and your hard drive is decouple-mounted. 1-1.5" thick open-cell foam will reduce noise much more effectively (especially higher pitched sounds) and inexpensively.

 

[dblevitan]

Well, my warranty is now gone, as well as a lot of the noise . The Silencer I put in there is still loud I guess, although much quieter than before. It's running a 12V, I might move it down to 7V but I want to see how the PS and case temps react to the change.
What I really want to get is a papst thermally controlled fan. Model number 8412NGMLV. You can see the specs on page 2 of this PDF file. Less than 10 dbA on minimum temperature looks nice . I believe Directron has them, but not with the temperature sensor. I'm e-mailing papst about where to find the sensor, and I'll post here when I get some more information on them.

mcvan, have you tried dynamat? I'm not too thrilled about glueing ugly foam on the inside of my computer, not only because of the ugliness, but also the temperature and smell. I won't be suspending my drive - my case uses drive rails, and if the PSU fan is running at 7V, it is almost silent. Also, just wondering, but I have a silencer at 12V on my CPU (attached to an SK-6) which is bascially silent, while a silencer at 12V in the PSU or on the case is somewhat loud. Any reasons for this?

Thanks,
David Levitan

 

[mcvan]

Originally posted by: dblevitan
What I really want to get is a papst thermally controlled fan. Model number 8412NGMLV. You can see the specs on page 2 of this PDF file. Less than 10 dbA on minimum temperature looks nice . ... mcvan, have you tried dynamat? I'm not too thrilled about glueing ugly foam on the inside of my computer, not only because of the ugliness, but also the temperature and smell. I won't be suspending my drive - my case uses drive rails, and if the PSU fan is running at 7V, it is almost silent. Also, just wondering, but I have a silencer at 12V on my CPU (attached to an SK-6) which is bascially silent, while a silencer at 12V in the PSU or on the case is somewhat loud. Any reasons for this? Thanks, David Levitan

PAPST fans -- the consensus among those who have used them is that their quality is inconsistent, much more so than their pricing would lead you to expect. If you get a good one, it's very quiet, but no more so than an undervolted Silencer fan that pushes the same amount of air. Yes, the super quiet Papst fans don't move much air at all.

The problem with thermistor fans is that you no longer have direct control over the speed -- and noise. Lots of folks (me included) find variable or changing noise levels MORE annoying than steady but not as quiet noise. Unless you know exactly what hot device you want the fan speed tied to, and can live with the up & down in fan speed, I wouldn;t choose a thermistor fan. In part, those PSU articles at www.silentpcreview.com are about how stop the thermistor from changing the fan speed.

SilentDrive is not to be trusted -- tends to cook 7200 rpm drives, lost of reports about failed drives in these things. You're better off with an aluminum sandwich.

Dynamat -- you've seen my comments already. Won't do anything for an already quiet PC unless the case is extra flimsy.

Smell from foam? I've never run into this. Try high density carpet underlay. It's really cheap, maybe free as scraps from a carpet store. If you use a hot glue gun sparingly, really easy to get off, too. The temp difference is irrelevant unless you overstuff your case & end up blocking airflow.

The fan noise difference on the CPU HS vs in the PSU --
1. The PSU fan actually faces the outside world. It is more exposed. The CPU fan is in the center of the closed PC case, more insulated. If you have a tower case that is against a wall under your desk, pulling the case 6" away from the wall, then adding a patch of foam (say 1 sq ft or more) on the wall directly behind the PSU fan will reduce noise noticeably.
2. The PSU itself is a little tin box that has a cavity resonance in the lower midrange (or high bass). The air in it will actually vibrate and accentuatew any fan noise close to that cavity resonance frequency. Minor, but there.
3. There are many airflow obstructions in the PSU -- all of which cause air turbulence, which causes noise.
4. The fan is usually firmly screwed down to the PSU casing, and this in turn is screwed down firmly to the back case panel. The case does vibrate around this area due to direct conduction of PSU fan vibes. If you try putting the PSU outside the case on a thin layer or foam, you'll find it usually makes less noise. In comparison, the CPU HS fan is more isolated from case panels.

 

[dblevitan]

Originally posted by: mcvan
PAPST fans -- the consensus among those who have used them is that their quality is inconsistent, much more so than their pricing would lead you to expect. If you get a good one, it's very quiet, but no more so than an undervolted Silencer fan that pushes the same amount of air. Yes, the super quiet Papst fans don't move much air at all.

The problem with thermistor fans is that you no longer have direct control over the speed -- and noise. Lots of folks (me included) find variable or changing noise levels MORE annoying than steady but not as quiet noise. Unless you know exactly what hot device you want the fan speed tied to, and can live with the up & down in fan speed, I wouldn;t choose a thermistor fan. In part, those PSU articles at <a href="http://www.silentpcreview.com">www.silentpcreview.com</a> are about how stop the thermistor from changing the fan speed.

Thanks for answering my question about the cpu vs. psu fan. I actually prefer thermistor fans to manually controlled fans. At 7V, the silencer is silent, but at 12 V (in the PSU) it is loud. Now when my cpu is running at 100% for a long time, the PSU does heat up (probably from the CPU), and I need the 12V to keep it warm. When the CPU is being barely used, the 7V fan is enough (the PSU is warm with the 7V, cold with 12V). Now it is true that I can manually switch back and forth, but if I forget by accident, or someone else is using the computer, I could be left with dead PSU and motherboard. I would much rather let a fan automatically control itself. As far as I understand, your problems were with the thermistor being placed right on the coils. Obviously, I would not do this, and I think that the benefits outweigh any problems.
I'll think about the carpet underlay. I've always noticed some smell around things lof that nature - not bad, just different, but then, I don't have much experience.
Thanks a lot for all your help,
David Levitan

 

[zeroidea]

SilentDrive enclosures work reasonably well, but I ran into problems when I installed 7200rpm drives in them (first a 30GB DiamondMax40, then an 80GB D740X). They basically get too hot to handle, and my computer started having odd problems (XP boots up, says it can't find some file, hangs)

I've heard or some people suspending their drives from the power supply, towards the back of the case, which might be a good idea; I think one of the reasons drive noise is so apparent is that they're usually up in the front, with no solid surface between you and them (since most cases have vents in that area).

 

[mcvan]

Originally posted by: zeroidea
SilentDrive enclosures work reasonably well, but I ran into problems when I installed 7200rpm drives in them (first a 30GB DiamondMax40, then an 80GB D740X). They basically get too hot to handle, and my computer started having odd problems (XP boots up, says it can't find some file, hangs)

Much worse than that has been reported: early HD failure due to overheating is not an uncommon report about these SilentDrives. I have a sample -- I think it's a badly engineered product.

I've heard or some people suspending their drives from the power supply, towards the back of the case, which might be a good idea; I think one of the reasons drive noise is so apparent is that they're usually up in the front, with no solid surface between you and them (since most cases have vents in that area).

Try the drive silencing / cooling ideas in the articles here

 

[zeroidea]

Very useful site. I just wish:

1.) I hadn't shelled out the money for Silent Drives
2.)something like the DIY sandwich was mass produced, and affordable

 

[AntecCSR]

TruePower has an onboard temp sensor that controls the fans speed.

We don't recommend using thermally/variable speed fans with the fan only connectors. Some work, some don't.

AntecCSR

 

[dblevitan]

That I know, but the fans in the power supply are individually controled from what I see. I was talking about replacing the fan in the PSU with a new, quieter thermally controlled fan. Right now I'm running a silencer at full voltage and its blowing cool air out of the PSU when there is little CPU activity.
-David

 

[mcvan]

Originally posted by: zeroidea
Very useful site. I just wish: 1.) I hadn't shelled out the money for Silent Drives 2.)something like the DIY sandwich was mass produced, and affordable

Sorry I can't help you with 1). With 2), something might come of it, you never know. I do have some aluminum plates. Cheap. If you're interested, let me know. Have a look at the HD cooling article, too, though: here