Suspend PSU

MalcolmC · Post by **MalcolmC** » Fri Mar 23, 2007 1:33 am

I think that the greatest source of noise in my system is my Corsair 520 PSU. It's pretty quiet outside the case, but when installed, it sounds far too loud for my liking. It is not a case of the PSU ramping up, but is (I assume) the vibrations getting transferred to the case and/or just more airflow noise because the PSU is now enclosed.

I will come clean and confess that I am using a Lian-li case (and I know that a lot of silencers are against these) but in my previous computer, which had a passive PSU, I did get this case (effectively) totally silent.

When I was building my new machine, I did as advised in these forums and used an Antec P150, but that was no use at all - the PSU ramped up excessively - presumably as a result of heat rising, rather than load - machine spec is fairly modest - core duo 6400, nvidia 7600, one Samsung drive. So I've gone back to my Lian-li case which has the advantage (like the P180) of having the PSU in the lower chamber, so there is no chance of heat entering from other components.

I have thought about changing the fan in the PSU, but would only want to do this if I was sure it would help.

So my second idea, and I don't know if nyone has tried this, is how about running a couple of rails out of the back of the case, and suspending the PSU off these - this should help airflow, cooling and also decouple the PSU, and therefore prevent vibrations? Has anyone tried it? If it's a daft idea, then please tell me.

Bluefront · Post by **Bluefront** » Fri Mar 23, 2007 2:06 am

I've been doing that in my last few setups, mostly to get a fanless Zen partially out of the case. I extended it about 1/2 it's length. No problems for me.......your idea might also help your setup. A different PSU might be a better idea however.

jaganath · Post by **jaganath** » Fri Mar 23, 2007 2:46 am

I think that the greatest source of noise in my system is my Corsair 520 PSU.

are you sure? have you done the identifying the noise sources thing?

is (I assume) the vibrations getting transferred to the case

If it is vibrations you should be able to feel it with your hand.

A different PSU might be a better idea however.

dunno, the Corsair is supposed to be pretty good.

kater · Post by **kater** » Fri Mar 23, 2007 3:04 am

Just a few quick ideas - you could play with silicon grommets, spacers, washers, younameit - various bits & pieces of silicon. You can prepare a custom mould and pour silicon in there, wait until it sets and just place the blobs underneath the PSU, on its sides.

MalcolmC · Post by **MalcolmC** » Fri Mar 23, 2007 3:08 am

Yes, I am certain the main source of the noise is the PSU (I've tried it with the other fans stopped).

Not sure if it's vibration of just pure air 'whoosh' - possibly a bit of each - I'll have a listen tonight.

Rerarding the PSU - I have tried both the Seasonic S12 energy + and the Corsair, which are the SPCR top two models - both sound pretty much the same - OK out of the case, but not ok when installed.

I'm never sure about this silent PSU thing - I've gone passive in the past, but I prefer a bit of cooling (for safety) - and most people here say that you might just as well have a fan if you can't hear it. Whilst I can get my case fans below my hearing threshold, every 'silent' PSU I have ever bought has been a real disappointment. Possibly I'm over-sensitive, or possibly, I'm no good at building quiet PCs.

jaganath · Post by **jaganath** » Fri Mar 23, 2007 3:40 am

every 'silent' PSU I have ever bought has been a real disappointment.

Well if you were expecting them to be silent (ie no noise at all even from like 2 inches) than I can see how you would be disappointed. Also, the marketing people chuck the word "silent" on just about any old piece of cr*p, regardless of actual dBA production. But if you're buying PSUs from the SPCR recommended list, and they're still too loud, then you must have an amazingly low ambient noise level.

MalcolmC · Post by **MalcolmC** » Fri Mar 23, 2007 3:55 am

No, it would be unrealistic to expect silence from 2 inches, but I would hope that it would be at a metre. As you can see, I have purchased the top 2 SPCR rated models (and quite a lot of others over the past 5(ish) years), so perhaps I have a low ambient noise level. But I don't think it's that low - I live in a village, and we tend not to have the television/music on 24/7, but I do have two teenaged children - so it's certainly not silent!

Possibly my expectations are too high, but I certainly purchsed these 2 PSUs on the basis that I would have to strain to hear them when working on the PC, and that I would not be able to hear them at all from my chair, which is 2 - 3 metres away.

I must say that I do have pretty sensetive hearing, but I don't think it is unusually so - I am 50 after all!

kater · Post by **kater** » Fri Mar 23, 2007 7:24 am

*Maybe* it's the case - yeah, I know, people have succesfully made alu cases very quiet, but maybe there's still something you can do with the case?

I've just fanswapped my S12 - I used Fander 120, which is audibly quieter than the stock Adda. I know it's hard to get Fanders outside Poland, but you could go with S-Flex or Nexus or YL. Also, I've plugged it into my Akasa manual controller. Since Fanders come with their own potentiometers, there are now two potentiometers in the setup. That allows me to switch off the fan and start it up and crank it up pretty high, as I please. I'm just saying that this might be an idea. Find a better fan the stock one, hook it up somehow, turn it's RPM further down - either go manual or auto, and you're done. Works for me. As the custom fan is set to such voltage that it barely starts, you can imagine how quiet it is. REAL quiet. Well, to be honest it didn't help a great deal, as the main noisemaker is still the HDD, even tho it sits in Scythe QD. Anyway, just for comparison - my S12 is now audibly quieter than before. Before, I could hear it from app. 1 m when out of the case and just sitting on the table. Now, I can't tell it's on from 20cm. It's so quiet I can hear its circuitry going chirp - not a big deal as it fades away at ca 20cm. Yeah, you have to void the warranty and get an extra fan, but otherwise it works like a charm.

MalcolmC · Post by **MalcolmC** » Fri Mar 23, 2007 11:18 am

Thanks for that thought Kater - I am quite tempted to do a fan swap, however, I thought that the generally held view was that you should not use a sleeve bearing fan in a PSU, and the ball bearing fans seem to be louder.

In the meantime, I have swapped out my Corsair for my old passive PSU, and all is tranquility once more - this does prove (at least to me) that it was the PSU that was making all the (perceived) noise.

However, for long term reliability, I tend to think that a PSU with a (very quiet) fan must be my best option (I've got two fans in my case, so if I can get a PSU fan that quiet, then I ought to be happy) - any ideas anyone?

jaganath · Post by **jaganath** » Fri Mar 23, 2007 12:18 pm

In a P180-type layout, where PSU fan is protected from heat from other components, I think a good sleeve fan should last at least 1-2 years. Good fans are Yate Loon,Nexus,Scythe S-Flex.

J. Sparrow · Post by **J. Sparrow** » Sat Mar 24, 2007 6:54 am

MalcolmC wrote:Not sure if it's vibration of just pure air 'whoosh' - possibly a bit of each - I'll have a listen tonight.

Vibrations are tackled with dampeners, but your PSU might be struggling for air. If case intake vents are too restrictive, then the fan will spin faster because of decreased pressure at the PSU intake.

MalcolmC · Post by **MalcolmC** » Sat Mar 24, 2007 8:04 am

It's definitely just air, not vibration; the PSU is in the bottom of my Lian-li case, but there is around 15mm under the PSU, and the case is drilled in a sort of honeycomb pattern underneath, so that the airflw should not be restricted. As a matter of interest, just before putting it all together, I drilled out all the holes (must be around 200 of them!) in order to maximise the airflow.

klankymen · Post by **klankymen** » Sat Mar 24, 2007 8:39 am

well if you're sure it's just airflow then my suggestion is moot, but i was going to say, instead of suspending the whole PSU, you could just suspend its fan....

but if its airflow.... no idea. is it ramping up, or is it loud from the start?

J. Sparrow · Post by **J. Sparrow** » Sat Mar 24, 2007 10:25 am

The Corsair HX520 is regarded as one of the best quiet PSUs around, so you might just have stumbled into a bad sample. How about trying a swap ?

MalcolmC · Post by **MalcolmC** » Sat Mar 24, 2007 11:01 am

Yes, but I had already tried a Seasonic S12 energy +, which is similarly regarded, and sounded just the same - perhaps I got two bad samples, or perhaps I am just too critical?

jaganath · Post by **jaganath** » Sat Mar 24, 2007 11:14 am

if the passive psu is working fine for you, just stick with that, a quality unit used at reasonably low loads should be no less reliable than equivalent fanned unit.if you're worried about overheating just stick a quiet fan near it.

Post by **CA_Steve** » Sat Mar 24, 2007 11:29 am

Just wondering.....if you isolate the power supply from the case...with grommets or whatever...aren't you also electrically isolating the case from the primary ground point?

jedster · Post by **jedster** » Sat Mar 24, 2007 1:50 pm

MalcolmC wrote:Yes, but I had already tried a Seasonic S12 energy +, which is similarly regarded, and sounded just the same - perhaps I got two bad samples, or perhaps I am just too critical?

I did a fanswap on my seasonic s12 330. i was intimidated at first but it turns out to be incredibly easy. i use a very slow spinning s-flex (probaby about 500rpm). makes a huge difference in noise. the s-flex are fluid dynamic bearing. i'm not an expert on these things but i assumed FDB was better than sleeve for high-heat applications since HDs use FDBs as well.

i think one advantage of the seasonic is that it is so efficient you can cool it with slower moving fans at lower system loads...

oh, i power the fan using an external source, though i could have used the 2 prong header inside the psu.

if you want to test your setup outside the case, just google about the green and black paper clip short circuit on the 24 pin cable that allows you to power up the psu w/o a mobo.

MalcolmC · Post by **MalcolmC** » Sat Mar 24, 2007 10:15 pm

Thanks for all the input - I suspect I will stick with the passive PSU in the short term and see how that works out, and in the meantime, do a fan swap on my Corsair, and possibly use this in the future.

psiu · Post by **psiu** » Sun Mar 25, 2007 4:13 am

MalcolmC wrote:Has anyone tried it? If it's a daft idea, then please tell me.

Bluefront wrote:I've been doing that in my last few setups,...

Just wanted to put those two quotes together.

Anyways about this:

CA_Steve wrote:Just wondering.....if you isolate the power supply from the case...with grommets or whatever...aren't you also electrically isolating the case from the primary ground point?

The electronics should all be grounded still via the power delivery, but a attaching a short lead of wire from case to psu might be a good idea to avoid static buildup. That would only be if the psu had no metal-metal contact anywhere.

Poodle · Post by **Poodle** » Sun Mar 25, 2007 7:06 am

You can see how I grounded my Corsair far down in this log:
http://www.sweclockers.com/album/?id=583

J. Sparrow · Post by **J. Sparrow** » Sun Mar 25, 2007 9:30 am

Poodle wrote:You can see how I grounded my Corsair far down in this log:
http://www.sweclockers.com/album/?id=583

Great! U120 wind tunnel! Can you post the results with different setups? In another thread, maybe