Seasonic M12 500W is buzzing

justlnluck · Post by **justlnluck** » Wed Mar 21, 2007 5:02 pm

In the past, I have had great experience with Seasonic PSUs. My first one was a 300W Seasonic Tornado. My second one was a 500W S12. I still own both of these PSUs and both are extremely silent.

Well you can imagine my shock and disappointment when I purchased a 500W M12 from Newegg last week for $154 only to find that it makes an electrical buzzing noise.

This is the most expensive power supply that I've ever purchased and it also happens to be the noisiest. Before purchasing Seasonics, I've had generic PSUs and Antec PSUs. Sure, I could hear their fans running, but I never had to deal with an electrical buzz.

The buzz is irritating because it isn't constant. It seems to depend on computer usage. For example, if I transfer a collection of photos from an SD card, I can hear it go "Buzz.....buzz....buzz....buzz... One buzz for each photo. Or if I rotate a picture, it goes quiet during the rotation process and comes right back after finishing.

I have hooked the PSU up outside of my case to verify the buzzing is indeed coming directly from the PSU and not motherboard or CPU. If I swap back to my old S12....perfect silence. Only the low hum of the fan is audible on the S12.

I am afraid that Seasonic is slipping on the quality of their PSUs. Is this a design decision that is causing the buzz or is it a defect? What are my chances of getting a quiet unit if I exchange this one? Anyone have experience with the M12 series? I thought I could trust Seasonic for high quality, quiet PSUs. That is why I paid a premium and didn't just buy a generic.

wwenze · Post by **wwenze** » Wed Mar 21, 2007 8:47 pm

Apparently a few of the newer Seasonics are exhibiting coil buzzing under certain load (light, medium, heavy, or whatever combination), but yours sounds serious considering the volume.

This is quoted from SPCR's own review of the M12:

Surprisingly, our sample had an undue amount of buzzing electrical noise with low 12V loads. The noise was worst with a 4A load on the +12V line, and got fainter as the load was either raised or lowered. The buzzing dominated the noise character at our 65W test load and raised the measured noise level significantly. Perplexed and a bit concerned, we checked three other M12 samples on hand. An M12-600 sample was almost identical to the review sample, while another M12-700 reached maximum noise at ~3A instead of 4A (on the 12V line). A fourth sample, an M12-500, exhibited no audible buzzing at any load. With all the samples, the buzzing basically disappeared above 4A load on the 12V line.

I suspect my S12 buzzes most loudly somewhere between 3-5A too, but since my system isn't able to draw that much power I can only be certain that it buzzes the loudest with CPU @ max power - 38.4W TDP + overclock/overvolt

Your 2800+ should also be drawing around 3-5A when doing the kind of thing you stated.
The difference is that, if you dig the forums deep enough, you'd see that in many cases the buzzes are ignorable. I mean, it would be perceivable @ 1m, but definitely not "dominate the noise character" as in the review and maybe in your case.

Or maybe it does, just that people's perceptions differ. Worth a check.

Edit: ok yea, mine "dominates the noise character" alright...

justlnluck · Post by **justlnluck** » Wed Mar 21, 2007 10:14 pm

Oops, my specs were way out of date. I forgot how long it's been since I was here! I guess I've had such success with a quiet PC until now.

The buzz isn't that loud, but it is rather high pitch. So I can still here the noise even though I have a Honeywell Air Purifier blowing across the room, I'm sitting at my desk, and the computer tower is down, below the desk.

The buzz is much more distracting than any air blowing. Infact, I wouldn't care if I heard fan noise. But this is a buzz that isn't smooth like air currents. It constantly turns on and off like Morse code. Although, when it turns off, it is only off for split seconds. It's just kinda funny when I'm transfering documents off an SD card, the buzz is rapid fire. If I'm loading a new program, the buzz goes away until the window finishes opening.

At this point, I feel kind of duped by Seasonic. They advertise quiet PSUs. In addition to the low fan noise, I had assumed they had designed their PSUs to not have coil whine. Neither of the previous units ever make a peep, so why would I predict otherwise for this one?

justlnluck · Post by **justlnluck** » Wed Mar 21, 2007 10:16 pm

I am shocked to read that your S12 buzzes. When did you purchase your PSU? I bought mine back in 2005. If you bought yours more recently, does that mean that all Seasonics manufactured today buzz? And more importantly, WHY are these buzzing when Seasonic made so many PSUs that operated perfectly with no buzzing?

wwenze · Post by **wwenze** » Thu Mar 22, 2007 12:31 am

That's exactly the kind of buzzing I had with an Abit VA-20. Except maybe it was much louder (audible over a 5000rpm fan).

For both my cases (PSU and mobo), undervolting or keeping the system cool helps, as well as certain cooler programs (programs that use the HLT command) like AMN Refrigerator when I was Win98.

Forcing the CPU into constant 100% load, by running prime95 or clicking the center button of a scroll mouse to enter scrolling mode.

Eventually sold the mobo @ half price after 6 months, after voiding the warranty by attempting to use silicone to seal up the coils.

But what's most interesting is that, for coil whine in some cases it happens when there's no load (like yours), in other cases it whines when there is (my current situation).

My S12 is bought in early 2006.

justlnluck · Post by **justlnluck** » Thu Mar 22, 2007 3:56 pm

Anyone else here own an M12?

jedster · Post by **jedster** » Thu Mar 22, 2007 4:59 pm

justlnluck wrote:Anyone else here own an M12?

it's a common problem from what i can tell. i don't have the problem on either my s12 330 or my s12 550w 80+

m12 700, very annoying buzz under light load. there's a thread somewhere in which someone called seasonic and they offered an rma with unit they guaranteed wouldn't buzz.

i almost did that but then decided to build a home media server which is always under heavy enough load that there is no buzzing.

jaganath · Post by **jaganath** » Thu Mar 22, 2007 5:21 pm

there's a thread somewhere in which someone called seasonic and they offered an rma with unit they guaranteed wouldn't buzz.

IIRC the RMA unit also buzzed, if you're thinking of PenDragon's thread.

Operandi · Post by **Operandi** » Thu Mar 22, 2007 10:14 pm

It's coil whine, as I posted over in your Anandtech post.

It's most likely an interaction between the Seasonic and the video card and/or motherboard.

What exactly are you powering with the Seasonic? If it's a lite load you might have better luck with a lower wattage S12.

justlnluck · Post by **justlnluck** » Thu Mar 22, 2007 10:59 pm

My 500W S12 makes no coil whine. I purchased the M12 because I was going to buy another motherboard and I needed another PSU that has the 24 pin connector. I also liked the idea of having modular connections, rather than having to stuff all the unused cables into my 5.25" bay. I had assumed that if my 500W S12 performed great with no noise, then the 500W M12 should perform similar. The M12 is attached to the exact same hardware as the S12. There really is no excuse for the whine. Seasonic used to be the most recommended PSU on this board. Is this not the case today? And if so, what is?

Poodle · Post by **Poodle** » Fri Mar 23, 2007 2:11 am

I have both a Corsair HX 520 and a Seasonic M12 700W. BOTH have coil noise. They are both the loudest part by far in each system.

I can't buy either Antec (two phantoms have died on me) or Seasonic after this. Every brand is turning shit while getting more expensive. Maybe reviewers should get their units for test in shops. I get the feeling reviewers get cherry picked stuff.

jaganath · Post by **jaganath** » Fri Mar 23, 2007 2:41 am

Poodle wrote:I have both a Corsair HX 520 and a Seasonic M12 700W. BOTH have coil noise. They are both the loudest part by far in each system.

I can't buy either Antec (two phantoms have died on me) or Seasonic after this. Every brand is turning shit while getting more expensive. Maybe reviewers should get their units for test in shops. I get the feeling reviewers get cherry picked stuff.

As for the units being cherry-picked, here is a quote from the M12 review:

Surprisingly, our sample had an undue amount of buzzing electrical noise with low 12V loads. The noise was worst with a 4A load on the +12V line, and got fainter as the load was either raised or lowered. The buzzing dominated the noise character at our 65W test load and raised the measured noise level significantly. Perplexed and a bit concerned, we checked three other M12 samples on hand. An M12-600 sample was almost identical to the review sample, while another M12-700 reached maximum noise at ~3A instead of 4A (on the 12V line). A fourth sample, an M12-500, exhibited no audible buzzing at any load. With all the samples, the buzzing basically disappeared above 4A load on the 12V line.

So this is a known problem with the M12's. I'm surprised to hear about the Corsair, but since it is made by Seasonic, it may have the same problem as the M12. Also, if the coil noise is the loudest thing in your system, maybe only a fanless PSU will really make a difference for you noisewise.

I had assumed that if my 500W S12 performed great with no noise, then the 500W M12 should perform similar.

The SPCR review definitely mentioned this problem.

Seasonic used to be the most recommended PSU on this board. Is this not the case today?

Statistically, Seasonic is still the most recommended brand. However, there have been increased reports of coil noise problems recently; whether this represents a downtrend in Seasonic quality control or simply reflects the concentration of Seasonic owners on these boards, too early to tell.

justlnluck · Post by **justlnluck** » Sat Mar 24, 2007 7:17 pm

The coil whine is quite noticeable. It's not like I had to get down on my knees to hear it. I have a Honeywell AirPurifier that is constantly blowing next to me. I don't care so much about a quiet system, but rather a cool running one that doesn't need excessive electricity. But the whine/buzz is high pitched enough that it is easily audible when sitting at my desk. The computer is tucked underneath the desk. The PSU is at least 3-4 feet away. I think the reason I noticed it so quickly is because it's always turning on and off in rapid succession. It only gets quiet during the loading of a software program or holding my cursor down and dragging a window up and down.

Poodle · Post by **Poodle** » Sun Mar 25, 2007 4:56 am

I've noticed that my Corsair makes a clicking noise when booting the system. It's quite loud and I first thought it was a wire that had been caught in one of the case fans...