PSU noise after upgrading Core2Duo to Core i5

[imported_Freeco]

I've upgraded my previous rig last Tuesday. Since then I noticed some weird sound coming from the case now and then (so not contineously). Can't really describe it, it sounds like a whiny/scratchy short bleeps. At first I thought it was my HDD vibrating against a metal part of the case, but that's not the case: it's still well suspended, not touching anything.
I opened the case and disconnected the DVD-ROM, DVD-RW, front-bay cardreader and soundblaster front bay, as those aren't required to boot.
I've put my ear close to all the individual parts and the sound seems to come from the PSU. That's a 3.5 year old Antec NeoHE 380W (see review of the 430W model for details on the PSU). I don't exclude the sound comes from the top of the motherboard, where the voltage regulators are. But I'd rather go for the PSU...

Old specs: http://www.silentpcreview.com/forums/viewtopic.php?p=304964
Changes after upgrade:
* Asus P7P55-M µATX board
* Intel Core i5 750 2.66 GHz quadcore
* Prolimatech Megahalems rev B heatsink
* 2x2GB Kingston DDR3 1333MHz 1.5V
* 80 GB Intel G2 SSD
* replaced the 500GB HDD by a 1TB green HDD some weeks ago
* replaced the defective nVidia 7600GS by a ATi HD5750 last December

I know a 380W PSU is on the low side nowadays, but according to this PSU calculator it should be more than enough. And as PSUs become more efficient when the load is higher, I don't want to exagerate with it's wattage.
With my current setup at 100% load and 20% capacitator aging the calc says I need a PSU of 317W. My old rig was calculated at 300W for the same load and aging.

But the thing is I haven't really stressed the new setup yet. The sound is already noticeable when 3 CPU cores are idling and 1 is doing light work, and the GPU load 0-2%.
Idling this setup draws about 90 to 100W from the outlet (measured!) and before upgrading I've never noticed this sound, even when really stressing the old setup (yes, incl stressing the HD5750). So I have problems to believe suddenly this PSU is giving up on me.
I guess that the power draw (V or A) of a Core i5 is different to that of a Core 2 Duo, and the old PSU isn't adapted for it. But that's only a guess.

Do I really need to look for a new PSU to get this annoying sound out of the way, or is there anything I can do/check? To be able to be sure of the source tonight I'll be trying to get the PSU out of the case without having to get all of the hardware out again. But even if the source is determined I'd still would like to know the cause.

 

[imported_Freeco]

in the meantime I figured out the cause: yes it's the PSU that makes noise, but it's only doing that when the load is low. Eg when running a Prime95 stress test that noise didn't come up once.
I read on another forum other brands and models of PSUs also suffer from this on the recent P55 chipset (might also be others). Even PSUs with higher wattages like 650 or 700W, so it's definitely not due to my PSU being too light weight.
It's actually caused by the power saving settings. Once you fix the CPU voltage in the BIOS the problem should be gone. Haven't tested it yet though, but at least I know what to play with.

Just out of curiosity, anyone around with a recent motherboard (P55 chipset preferably) that has a Nexus Value 430 or Enermax Modu82+ 425 PSU? I'd like to know if I'd buy one of those if the problem would be solved as well.

 

[Stefan Payne]

The Antec NeoHE isn't that good.
But a coil whining PSU on a P55 system isn't that rare...

Maybe an other PSU will do it but that's not certain...

Oh and the cause for that are the new energy saving features like C1E...
Disabling that might help.

 

[Zap]

Check in your motherboard BIOS for settings relating to "Spread Spectrum" and see if toggling any of those changes the nature of the noise.

 

[imported_Freeco]

well, not that good news I'm afraid... this morning I wanted to boot the PC to start teleworking and nothing happened. Pressed the powerbutton again, still nothing. Then I noticed some smoke was coming from the PSU exhaust
I unplugged everything, and will be getting all of the hardware out anyway. I guess the PSU is dead, but I'll test it once more when everything is out of the case.

Don't know what happened. Yesterday everything worked fine. The only changes that were made was removing the front fan and reconnecting my card reader to a USB header on the mobo. And I've connected if correctly!

bummer...

edit:
got everything out in the meantime. Connected the mobo to the PSU, installed the SSD & GPU on my desk. It still boots to Windows, so it's not dead. Ow, and now I'm 100% the sound is coming from the PSU. I've openend it, and I can here it very clearly near the location where are the cables are soldered to the printboard. There are some capacitators and coils on that side.

Bottom line: the trust in this PSU has dropped. I think it'll be better replacing it. My preference would go to the Nexus Value 430, but Nexus products are nowhere to be found locally. As I don't want to wait till next week for the new PSU, I'm thinking of buying the Enermax Pro82+ 425 in a store nearby.

 

[RussianSensation]

. My preference would go to the Nexus Value 430, but Nexus products are nowhere to be found locally. As I don't want to wait till next week for the new PSU, I'm thinking of buying the Enermax Pro82+ 425 in a store nearby.

I am not sure what the pricing is like where you live, but I'd go for Corsair VX550 (if on a budget), or Corsair 650 or a Seasonic Modular series. Enermax PSUs are generally excellent but overpriced in North America. My personal recommendation is to spend $20-$30 more on a better quality power unit than to skimp out and get another value PSU for $50. Also, a 425W PSU is very weak if you ever plan to pair it up with a faster graphics card like 5870 or GTX470, etc. I wouldn't get any PSU less than 520-550 Watts (minimum).

7 midrange 600W PSU compared: http://www.madshrimps.be/?action=getarticle&number=9&artpage=4521&articID=942
CoolerMaster SilentPro M600

 

[imported_Freeco]

I got the Enermax Pro82+ 425W last Friday. The local store had them in stock, and price was OK.
425W is more than enough for me. Stressed my setup only draws about 250W from the outlet. (should update my signature)

 

[Modelworks]

It is rare but what can happen is, over time, very loose coils vibrate against the ferrite core and eventually the enamel coating wears off shorting out the coil.

 

[Bill Brasky]

Hmm. I'm having the same high pitch PSU 'coil noise' issue as well, where it's only audible during idle. I've begun playing around in the bios, and I'll report back if I have succes with the voltage control.

Corsair HX520w / i5 / ASUS p7p55d / xfx 5850

 

[Blastman]

2 threads going on this same topic and I posted in the other one.

Anyway, I just built a i3-530 with a Gigabyte M/B and was getting a rattling/vibration sound in the case with my 8 year old Enermax 350w psu.

I believe there is an issue with some PWM (pulse width modulation) fans and some PSU's, and when combined they set up some sort of harmonic vibration and/or noise.

I went into my BIOS and set the auto-CPU-fan speed adjust from PWM to Voltage. So the stock HSF (Intel) rpm is now being varied by voltage rather than PWM. Presto -- noise gone.

If you have a PWM/voltage setting for how to vary the speed of your CPU fan, you might check the settings to see is that resolves the noise issues.

If not, you may have to consider getting a new psu or an aftermarket HSF with a voltage regulated fan.

 

[imported_Freeco]

Don't think that's a solution to everyone: my fan speed settings were completely disabled in the BIOS, as I use Zalman FanMates to manually control the fan speed myself. And I still had the noise.
But if it works for you, indeed maybe it's good for others too

 

[Blastman]

Don't think that's a solution to everyone: my fan speed settings were completely disabled in the BIOS,

Could the default setting still be PWM even with auto fan settings disabled?

 

[Bill Brasky]

snip

edit: It's 100% the PSU. I thought it was coming from the cpu socket area. Not the case at all. I used a rolled up piece of paper to my ear to help identify the source. My theory is that the culprit is the gpu + psu combo not playing nice.

edit2: holy balls its loud. This sucks.

 

[imported_Freeco]

definately not the GPU that's the cause: I upgraded my GPU last December and that posed no problem at all for the PSU. It only started buzzing after upgrading the mobo/cpu/ram

 

[Bill Brasky]

definately not the GPU that's the cause: I upgraded my GPU last December and that posed no problem at all for the PSU. It only started buzzing after upgrading the mobo/cpu/ram

Yeah I think you're right. It seems to be a strange combination of intel c states, mobo, and psu. I disabled all c-states in bios last night after I made that post, and I haven't heard as much as a mouse sqeak from my box.

The only thing that sucks, is that now turbo isn't working. Guess I'll have to do a manual overclock.

 

[Blastman]

edit: It's 100% the PSU. I thought it was coming from the cpu socket area. Not the case at all. I used a rolled up piece of paper to my ear to help identify the source. My theory is that the culprit is the gpu + psu combo not playing nice.

Yes … that's where the noise was coming from in my system too -- the psu!

I was fooling around with ET6 (Easy Tune 6, a Gigabyte utility to adjust the fan speed of CPU and monitor hardware) trying to see how low I could get the rpm of the stock fan on the Intel CPU to run. Interestingly enough, running with PWM the lowest was ~ 1100 rpm. When using voltage to set the fan speed, I can get the CPU fan speed to auto down to ~ 500 rpm (CPU idle) where it is very quiet, much lower than on the PWM setting.

The noise coming from the psu also happened to disappear when I switched the auto fan speed adjustment to voltage (from PWM).

 

[Bill Brasky]

Well I just did a complete case fan + controller overhaul. For anyone that's interested, I bought 3 of the Scythe Slip Stream pwm fans and they're amazing.

But I am now 100% sure that a high pitched noise is also coming from the cpu socket area, which is magnified in my situation because there is a case fan on the top panel of my p180. The source of this noise only became obvious once the rest of the system got more quiet.

The psu noise was fully eliminated by disabling the c states and turbo in bios. I'm happy about that because it was borderline obnoxious. But after many hours of googling, it seems there are many other asus and gigabyte p55 motherboard owners with the same woes. A few tried to RMA, but the replacements suffered from the same issue and they ended up going with another manufacturer.

eidt: After reading this thread at gigabyte forums, it seems someone also had luck manually setting cpu voltage to 1.2v. I'm going to try this as well.

edit2: manual voltage didn't help the socket area noise, except that now the fans spin faster and muffle it better.