seasonic m12d 750w buzzing

Terje · Post by **Terje** » Sun Mar 15, 2009 1:42 pm

Hi,
got the m12d for a new PC. Quiet and nice in most cases, but when the core i7 cpu is under load, it buzzes. Not screamingly loud, but easily the most annoying sound from the PC which otherwise is fairly silent.

I assume its coil noise of some kind.

Anyone else experinced buzzing from this PSU?

Was wondering if I should take it back and complain, but I suspect the buzzing is low enough that in a regular shop, they will not hear it if they try it

elpibe10 · Post by **elpibe10** » Mon Mar 16, 2009 1:53 am

Are you sure the buzzing is from the PSU ?

Also, are you using any inverter in your house (eg. Inverter aircon, refrigerator, etc.) ? A modified square wave inverter (instead of true sine wave ones) will cause buzzing on practically every brand of PSU.

walle · Post by **walle** » Mon Mar 16, 2009 4:29 am

The components in these power supplies are first class which leads me to believe that its caused by a poor attachment/gluing job during the assembly process, I suggest you take it back to the retailer requesting a replacement unit ASAP.

Note:
I've had the same experiences with other manufactures in the past, though never (knock on wood?) with any Seasonic units, to date.

Good luck mate and please keep us posted.

Terje · Post by **Terje** » Mon Mar 16, 2009 6:37 am

elpibe10 wrote:Are you sure the buzzing is from the PSU ?

Also, are you using any inverter in your house (eg. Inverter aircon, refrigerator, etc.) ? A modified square wave inverter (instead of true sine wave ones) will cause buzzing on practically every brand of PSU.

I am very sure it if from the PSU. Its loud enough that it is easy to hear where it comes from.

If there are any inverters, probably, but nothing nothing that has caused even nearly as much buzzying from any of the other electronics in the apartment (except from an old shuttle I had, but there it was coils on the motherboard which was whining).

Its pretty unique to this setup.

This is a core i7 920 with a 4870 crossfire on a MSI eclipse board (don't sound like it should be silent by any means, I know, but its doing quite good now).

I did not some testing and I found out that:
- no overclock on the 920. The buzzing is audible, but tolerable when idle (need to put my head towards the rear of the computer to hear it clearly). More annoyingly, gets stronger when when there is activity of various kind on the PC
- Remove one graphics card and overclock 920. Almost no buzz
- Keep both graphic cards and overclock the 920 to 3.6GHZ, buzz heaven also when idle.

Since I am moving stuff around here anyway between my old PC (which I plan to put into server duty), just from curiousity, I will hook up the enermax modu 82+ and see what it does.

I am increasingly ready to visit the shop and request a replacement unit. A PSU this expensive should not buzz unless you throw water in it

Terje · Post by **Terje** » Mon Mar 16, 2009 7:04 am

Terje wrote: Since I am moving stuff around here anyway between my old PC (which I plan to put into server duty), just from curiousity, I will hook up the enermax modu 82+ and see what it does.

Moved the Modu 82+ 625 Watt PSU from the other PC.
I cannot say that it is completely without any hizz/buzzing noise, but when I need to put my ear within centimeters of the PSU to hear that noise, then I believe it is acceptable even for the most fanatic silentpcreview member

Taking my seasonic back to the shop asap.

elpibe10 · Post by **elpibe10** » Mon Mar 16, 2009 7:10 am

I mentioned inverters because it took me quite some time to figure that out when my Antec Signature psu buzzed .... along with my PCPC Silencer 750W and most of my Seasonics (except the Corsair HX520 and HX620 which is kind of a surprise as they are made by Seasonic).

Found out that the culprit was a newly installed Panasonic inverter aircon. Had to replace it with a non-inverter one even though it was only 2 months old. The buzz from the PSUs was driving me crazy.

If your M12D is indeed buzzing, I would suggest that you switch off whatever inverter that's in your house and try again. If the buzz persists, then the fault could most likely be the PSU itself.

walle · Post by **walle** » Mon Mar 16, 2009 11:16 am

Terje wrote:Taking my seasonic back to the shop asap.

Sounds good and good luck, hope you get a replacement unit.

elpibe10 wrote:Found out that the culprit was a newly installed Panasonic inverter aircon. Had to replace it with a non-inverter one even though it was only 2 months old. The buzz from the PSUs was driving me crazy.

My interpretation (as based on your description) is that the Corsair units were assembled correctly whereas the other units where not, or else the Corsair units would have been equally effected by the inverter aircon, not to say that Iâ€™m right though.

Terje · Post by **Terje** » Tue Mar 17, 2009 9:07 am

The shop was kind enough to let me replace it.

However they were worried that if I took another m12d again, it might actually just be that the components did not like each other, so they wanted me to select a different unit.

I know the modu 82+ is very silent and nice but I also know that I have had a couple of unplanned reboots when using the modu82+ with the crossfire 4870, and I have seen the system spike up above 500 watts at times, so I was suspecting that I might be close to its max.

The only other silent (according to the people in the shop) 700+ alternatives they had was the Antec signature 850 and the new enermax revolution 950 and 1050.

After reading reviews on my mobile for an hour in the shop, I eventually headed for the revolution 950 despite its completely outragous price.

I could not find a lot of good reports on the noise, but I did observe anandtech reported an idle noise of 18db and that it does not start spinning up the fan until about 550 watt, which sounded great.

The little info I found on the Antec indicated that it was very silent, but maybe spinning the fan up a bit early when under load.

I tested the modu 82+ 625w and the revolution side by side on the floor here before installing and to sum it up:
- the modu 625w is quite a bit more silent. The revolution I got would probably not pass the test with most SPCR users when running in an open setting like this. It is decent, but not silent. The fan is more audible as it clearly push more air at idle, but most annoying, it does have some level of uneven mechanical noise. Difficult to describe, it oscillates a bit. Never quite heard anything like it, but the fan is not touching anything. I think it might be some sort of issue in the bearing (inbalance maybe). I would not be surprised at all if other samples does not have this noise.

- The good thing is that when installed in the P180, its barely audible. That is, seems to occur in a way that makes it audible outside of the fan, but not so much on the air outlet of the PSU. That is, as strange is it might sound, it seem to stays inside the cabinet.

- The fan on the revolution is a weird 135mm Not easy to replace.

- The revolution is the biggest (longest) PSU I have ever seen. You will have to sacrifice the lower fan in the P180 to get this bugger in. No chance to make it fit with a fan there. On the good side, I suspect it moves enough air even at idle that I don't think you will have a problem with a couple of SPCR selection of silent (cool running) HDs. I would be careful with more than 2 though.

- Cool enough, put your ear to the revolution and it hums like the hum you hear when you pass one of these larger trafo building or when you go pass a power station. This thing hums like it was the rambo of PSUs

- The hum is silent enough that you will not hear it more than a few cm away. It does produce some vibration in the PSU though. Nothing that cause trouble with my P180 though, but with a less sturdy cabinet, I am not so sure.

Conclusion, I suspect my revolution has a less than optimal fan sample, however even if it was a perfect sample, it still makes more noise than the modu 82+ low power draws.

On the good side, in my P180, the noise seems to not be a problem since the lower section of the cabinet insulates noise pretty well and I normally got the P180 on the floor on the side of my desk where the desk screens off some noise as well.

Right now, with regular desktop work in windows 7, the two 4870 GPUs are idling at 46C and 50C (Arctic accelero S1 with 1000 rpm 100mm fans on them to cool the PWMs), the core i7 920 overclocked to 3.6GHZ is at 51C.

This thing is more silent on the floor halfway under my desk right next to me than the 24" alu imac on my desk and the slight buzzing from the other monitors (not enough noise to bother me, but its there).

All in all, I was worried when I first turned the revolution on and heard the noise, but once inside the P180, I am reasonably satisfied with it.

This thing can be an spcr candidate given the right cabinet and cabinet placement. Get your head close to the PSU, and you will hear the rather annoying mechanical noise from the fan, but get it at least 50-100cm away in a well dampened case, and at least my sample is quite acceptable.

walle · Post by **walle** » Tue Mar 17, 2009 12:39 pm

Excellent post Terje and thanks for keeping us posted (well, more then posted really, almost a review thingy going there), but more importantly; Iâ€™m glad you got it sorted.

Post by **MikeC** » Wed Mar 18, 2009 9:45 am

Terje (and others who have buzzing problems) --

It struck me as odd that a 750W PSU could not handle the power load of your system; even with both 4870s at full load, the whole system be only ~50% of the {SU rating. I also know how "strong" (for want of a better word) the M12D design is.

Anyway, I came across this thread in the Corsair support forums. It seems odd, but....

http://www.asktheramguy.com/v3/showthread.php?t=75330

A buzzing electrical noise (not a fan noise) was comming from my power supply.(new PC : I7 920, DDR3, HD4870, Gigabyte X58-UD5,.. Corsair TX650).
I've made some test with another new power supply(not a corsair one) and the noise was still there .. so I've started to search why...

It seems that the problem was comming from the 'powersaving' systems use by Intel processors. Something seems to be wrong when they are activated in the bios ( a kind of incompatibility between MB-CPU-Graphic-Power working together).

Before the RMA procedure I suggest you to try to set the 2 parameters :

C1E and EIST (Enhanced Intel Speedstep Technology) to disable in the MB BIOS.

It seems this solution is working fine specially for new PC (Core 2 duo or better).
Hope it will help some of people reporting buzzing noise to avoid unnecessary RMA.

Check the forum link -- many people are reporting success getting rid of the buzzing.

Terje · Post by **Terje** » Wed Mar 18, 2009 10:54 am

MikeC wrote:Terje (and others who have buzzing problems) --

It struck me as odd that a 750W PSU could not handle the power load of your system; even with both 4870s at full load, the whole system be only ~50% of the {SU rating. I also know how "strong" (for want of a better word) the M12D design is.

Anyway, I came across this thread in the Corsair support forums. It seems odd, but....

Interesting stuff. Reminds me of the quite annoying core2duo laptop whine which has also been attributed to power save states. Many claim it stops if you disable C3/C4 states.

Unfortunately I cannot test this anymore since the PSUs I have now do not have this issue. Would have been an interesting test.

Just regarding the power load above. If I run two super pi and a furmark my watt meter shows around 450w.

If I play something like crysis, it normally runs around 380w, but it can have short term spikes at times towards 500W (480 is the max I have seen so far).

Note that this is with the CPU overclocked to 3.6 GHz, and with that overclock of course also a fairly high NB and memory frequency.

A bit more than 50% of the m12d 750, but I agree, it should in any case not have been a problem at all (which is why I bought it).