Hey there,

So I've been looking recently to try and silence (or quieten, at least) my computer. So I've gone through all the parts and tried to silence them all:

CPU - stock PWM fan from Hyper 212+, lowest fan curve possible in BIOS
GPU - stock cooler, 40% constant all the way to 80C - lower values cause the fan to whine faintly
PSU - the fan is the noisiest fan I have, and makes a kind of whirring sound that is hard to describe
Case fans - virtually inaudible - AP-13s running at their constant 1150RPM
HDDs - In the CM drive mounting thingies, with elastic bands partially detaching them from the drive mounting thingies, still vibrate through the case and I can't attach the right side panel due to beat frequency

So I've been thinking that there isn't much left I can do, besides replacing the PSU (the fan is 135mm, and I'm not sure I'd be confident replacing it myself anyway - although replacing the whole PSU would be expensive), suspending the drives (not sure this is something I particularly want to do) or buying drive bay things, and working on the case.

So I'm thinking seeing as the system is relatively quiet anyway, foam, or some other form of dampening material, might be the way to go. I just figured I'd sign up here to get some opinions and to see what recommendations people have for dampening materials.

Anyway, what steps do you recommend I take?

Cheers

cheap, easy and surprisingly effective==> put a Self-Sticking Vinyl Floor Tile on the left side door panel

How is the PSU positioned?
Is it at the top or the bottom of the case. If at the bottom is the fan facing the floor? If it is facing the floor, try flipping it over and see if that fixes the fan issue.
If it's at the top is there space for it at the bottom of the case?


When you place the PSU upside down you trap heat inside it, with requires the fan to spin more.

The PSU is at the bottom of the case, with the fan facing down. I could try flipping it, but when I say it makes a whirring noise, I basically just mean that it's not the quietest of fans - I don't think it could get any quieter. Still, would it be likely to run more quietly with it oriented the other way up? If so, I'll give it a go.

I'd still have a go at cable tying a 120mm fan into the PSU, you've got nothing to lose.

The fan profile for this PSU does not look too bad, the 135mm fan speed starting at around 650 rpm and rising to around 800 rpm at 50% load. A fan of this size at those sorts of speeds would normally be classified at quiet, but it may not be if it is an issue of tone or bearing noise. This PSU is slightly unusual in that the fan is normally attached to the PSU cover. With the XFX the fan is fitted to a separate metal frame which is screwed on top of the PSU and is independent of the cover. If the frame is loose it could be a source of noise, or maybe it is just a faulty fan. If the PSU is still within the guarantee period you could consider a warranty claim.

I'd say that the PSU is a quiet one, to be honest, but as my PC is generally quite quiet it's still one of the noisier components in my system. Unfortunately it's not under guarantee though, as I bought it as an ex-review unit so it had been opened up.

The chances of fitting a replacement 140mm fan could be slim because the mounting tray looks to be sized to just about fit the 135mm fan. So the options would seem to be (a) fit a replacement 120mm fan, as already suggested, using cable ties through the existing 135mm mounting holes or (b) fit a 7V fan resistor cable between the fan and the PSU circuit board.

This is the Zalman 7V resister cable which I have used before http://www.quietpc.com/gb-en-gbp/products/casefanaccessories/resistors. The 135mm fan is a 2200 rpm model, but in the XFX is set to a maximum speed of around 1900 rpm. So a 7V cable would cut the top speed to around 1100 rpm, and reduce the minimum speed from about 650 rpm to circa 400 rpm. This might require a bit of work because the existing fan and the 7V resistor fan cable use different pin/socket spacing. I have used a sharp craft knife to split/reduce the size of fan connectors to resolve this.

A simpler alternative if you have access to soldering equipment, or know someone who does, would be to remove the resistor from the Zalman cable and solder it into one of the 135mm fan's power supply leads.

To be honest, I think I'd rather fit a new 120mm fan than try adjusting anything on the current one with resistors etc. - I think it's just the bearing that's making the noise, although I don't know enough about fans to be sure.

Do you think a regular depth 120mm fan would be able to fit inside the casing of the PSU fine - would I be able to put the top of the PSU back on and screw it down after fitting the PSU?

Yes, the existing 135mm fan is 25mm deep, which is a standard dimension. The only thing you maybe have to watch is that the existing fan starts at around 4V and you need a replacement fan with this starting voltage or lower. A potential candidate is the Scythe Kama Flow 2, in either 1900 or 1400 speed. If you want to be sure the fan will be quiet, the 1400 rpm model might be the better choice, available from sources such as this one http://www.purecoolpc.co.uk/buynow-id-10607,20608-Scythe-Kama-Flow-2-120mm-1400-rpm-120x120x25mm.html.

There is a review for the 1400 Kama Flow 2 here http://www.xbitlabs.com/articles/coolers/display/120mm-fan-roundup-1_14.html.

Does your PS look like this one XFX XPS 650W XXX Edition Power Supply? If so then the review of this 850W model shows the fan mounting:
XFX 850W Black Edition

It's the underside of the fixing tray that's the issue. As this shot shows it is around 25mm deep but a fairly tight fit around the 135 mm fan.



So as said already, a 140mm probably won't fit but a 120mm with cable ties should be OK.

Ah well, I still have a huge choice of 120mm fans. Well, not so huge if it has to be 4V or below starting voltage, but still.

Okay, I wrote this just before your latest post: :p

Yep, that's my power supply. There are actually pictures of the fan mountings on the actual review my PSU was used in. So, a few questions definitely remain. Firstly, how can I be sure that the fan I'm using will keep the PSU cool? The last thing I want is an overheating PSU, for obvious reasons. Secondly, what about PWM fans? I've never heard my PSU fan spin up, but could it still be a 4-pin connector? EDIT: I see that the original fan is only a 2-pin, so I guess there won't be a 4-pin on the PSU's thingy. I just don't want to end up with a 3-pin fan that's too loud (or no quieter than the current one) with no realistic way of turning it down besides replacing it with a different model. I basically don't want to go to all the effort of buying things, opening my PSU, pulling apart all the cables from my rig, only to find that it's not really any quieter, or worse, that my PSU is getting really hot.

The PSU fan voltage control is based on its internal temperature. As the power supply is bottom mounted the only source of heat is going to be the load placed on it. Like many Seasonic based units, the fan profile up to around 50% of load, or the temperature associated with that loading is relatively gentle - from around 4V to about 6V. So the worst case scenario is probably that you might end up with a quiet 120mm fan running at 600/700 rpm if the PSU gets a bit hotter due to less fan airflow.

Wait, how can it control the speed of the fan if it's a 2-pin connector?

Also, I read somewhere that the 650W model wasn't a Seasonic. Well, as far as I remember.

Wait, how can it control the speed of the fan if it's a 2-pin connector?

Usually the black wire stays at 0 volts and the red wire varies from around 4 volts at low power output towards 12 volts as the temperature rises with increased power output.

Okay, this is beyond me.

But really, all I need to know is that if I plug in two of the three pins on a regular fan connector to the header in the PSU, it won't just run the fan at full speed?

Correct. The fan will run slowly. The PS internal fan header is usually different than the standard mainboard connectors and many folks just cut, strip, twist and tape.

Nice. As for the fan, since I really like the AP-13s that I use as case fans, what would you say to the AP-14?

http://www.scythe-eu.com/forum/4866-post1.html

Start voltage OK, ball-bearing fan, worth a try.

Okay, thanks.

Now I just need to decide whether I'm confident enough to open up my PSU and perform modifications to it.