Corsair PSU Electrical Buzzing Noise Under Load

Power Supply Coil Whine

This article demonstrates one type of electrical buzzing noise (coil whine)  that computer power supplies can generate under load. In this case, the unwanted noise comes from a Corsair HX100i Platinum PSU – a supposed premium product and chosen for a  silent PC build because of its Zero RPM fan mode and its promised quiet and efficient operation.

Power Supply Units (PSUs) should not sound like this. This one was sent back for an exchange and the replacement was good.

During general desktop use, the power supply was silent.  When required to fulfill demanding power requirements though, the PSU started to make a buzzing sound  like sparks jumping the gap of a Van de Graaff generator and in some instances, like chirping crickets.

It was difficult to determine the power supply as the source of these noises when it was in  situ within the PC case. Noise from cooling fans and spinning hard disk drives can make the noisy culprit difficult to determine by putting your ear inside the computer case. The only way I could make a determination was to remove the power supply from the case and place a demanding load on the PSU. This made it much easier to identify the noise source.

I used the Furmark GPU stress test to make the power demand.

This video demonstrates the electrical buzzing noise from the Corsair HX1000i power supply when put under load and how the noise stops when that demand is removed.

As per Corsair’s recommendations for curing noisy PSUs, all power saving options were disabled on the motherboard and in Windows prior to recording.

  • 02 seconds  : mouse click to start the Furmark GPU stress test. Straight away, the unwanted PSU buzzing noise can be heard.
  • 12 seconds : this is the noise from the GPU fan. However, the electrical noise from the Corsair PSU can still be heard.
  • 24 seconds : mouse click to end the Furmark GPU stress test. The PSU noise and the GPU fan both stop.
  • 29 seconds : the Furmark GPU stress test is repeated and the Corsair power supply noise can heard after the mouse click.
  • 48 seconds : Corsair power supply details shown during the Furmark GPU stress test. Power draw 187W in and 172W out.
  • 59 seconds: Furmark GPU stress test ends and PSU noise stops.

How to Reduce the Minimum Fan Speed of a nVidia GT430 Graphics Card

How to Reduce the Minimum Fan Speed of a nVidia GT430 Graphics Card

If you have an  nVidia GeForce GT 430 graphics card and you want to reduce the card’s minimum fan speed, then these instructions should help you achieve that with relative ease.
ASUS 1GB GeForce GT 430 PCI-E 2.0 with Low Profile Bracket


Cards like the ASUS 1GB GeForce GT 430 graphics card are often incorporated in slim Home Theatre PCs (HTPC) because of their low profile fit and their relatively low cost coupled with their high performance at decoding High Definition (HD) video content.
These models have a cooling fan sat inside the heat sink that helps govern the temperature of the GPU. The minimum fan speed is set in the card’s BIOS as a percentage of it’s top rotational speed. My card’s minimum fan speed was set at 60%. I had read of other minimum fan speeds, such as 65%, when I started to research this.
Initially, the card was quiet enough for use in my HTPC. Over time however, the fan became louder at it’s minimum, idling speed. And I wanted to quieten it down by reducing it’s minimum speed and adjusting the fan’s speed v GPU temperature curve. I found I could do most things with software except reduce the hard-coded minimum fan speed. A BIOS hack was required.
I found that a great number of people had been asking how to do this hack via many different internet forums. Solutions were not clear; the posts were old and a lot of the links for the necessary software were dead.
I found two noteworthy sets of instructions here to flash the device from a bootable usb stick running DOS. No matter how I tried though, I couldn’t get mine to flash. And I think it’s because the software revisions have moved on.

Guide for Flashing BIOS of nVidia GPU –
Bootable USB Drive, Flashing nVidia GPU – Recovering From a Bad Flash –

It’s worth checking out how to recover from a bad flash and be prepared for such an event.

What You Will Need

I did everything in Windows 7 x64. There was no need to create a DOS bootable usb drive. All I had to do was re-boot the PC when the BIOS flash reported as being successful.

nvflash (windows version)

EVGA Precision X


Download NiBiTor and nvflash (windows version) and unzip them if necessary by extracting them to their own folders. Remember their locations.
Download and install EVGA Precision X on your computer.
Click once on Windows Start and type in cmd where it says Search programs and files. Do not press Enter.
The cmd program should be shown at the top of the list under the heading: Programs. Right click on it once and select Run as administrator. Click Yes when prompted.
The command console should appear and look something like this:

Double click the nvflash folder and right click on the directory path at the top of the folder window.

Select Copy address text from the context menu.

You can see here that my nvflash folder resides on my F drive at
F:\GT430 BIOS FLASH\nvflash_windows_5.142

Now click on the cmd window and type cd and a space. Right click and select paste.
The full directory name should be pasted into the window like this:

Press Enter to change into that directory. Notice that if you have your files on a different drive to C, you will have to change to that drive before hand like I have done here with F:

Back Up the Original ROM

In the cmd window, type

nvflash -b original.rom

and press Enter

This will make a back up copy of the nVidia card’s BIOS to your nvflash directory with the filename
You can use a filename of your choice.
It is important at this stage to make back up copies of this BIOS image. Store a copy on a usb stick. Store a copy on another PC. Should things go wrong, you will need access to this file. A bad flash may prevent your card from outputting any display at all. So it’s no good just to have the one copy on that machine. You won’t be able to see to get at it!

Modify the BIOS with NiBiTor

Go into your NiBiTor folder and run the program.
Go to File > Open BIOS…
and select the file original.rom from your nvflash directory

You should see something like this as you browse the different tabs:

Change the Min fan speed here to something like 30

Then go to File > Save BIOS…

and select a new name for you modified ROM. Ensure you don’t overwrite your back up file.

Save this file to your nvflash directory. I used the filename:


Ready to Flash the BIOS?

The files in your nvflash directory should look something like this:

The nvflash files; the modified BIOS and your back up file.
Note: I have two back up files of the original BIOS in this screenshot entitled backup.rom and GF108.rom. You will just have the one back up file entitled original.rom
WARNING: The next command starts the flash process!
Ensure that this process is not going to be interrupted by anything.
Click on the cmd window once more and type:

nvflash modified.rom

and press Enter

The BIOS will be flashed with your modifications. Wait until the program reports success, then reboot your PC.
In the event that the flash goes wrong, you will need your original BIOS rom file to attempt a blind flash using a usb stick. Details of how to do this are explained in the links I gave in the introduction.

Controlling Fan Speed

Launch EVGA Precision X

  • Tick Windows Start Up so the software runs every time Windows boots. If you click on the settings icon (the two gears in mesh – top right) you will be able to select Start minimized if you don’t want this screen to appear every time Windows starts.
  • Change the minimum speed of the fan. (I believe that there is another value in the BIOS that prevents the fan from stalling at low rotational speeds). I found  I couldn’t enter values less than 31% even though I’d set the minimum value in my modified BIOS to 20.
  • Ensure Auto is ticked.

Now click on fan curve and ensure that Enable software automatic fan control is ticked

Here you can drag the points on the curve to create your own profile of fan speed vs GPU temperature. Experimentation and monitoring is key here. Spend a while monitoring your GPU temperature under different conditions of load. Playing games for example will cause the GPU to generate lots of heat. That heat has to be dissipated effectively or your GPU will burn out.
This profile works for me but the sole use of my card is the decoding of HD video. What I’ve done here is:
  • halve the fan’s minimum speed
  • keep the fan at it’s new minimum speed until the GPU temperature hits 68’C
  • then increase fan speed accordingly to maintain 68’C – 74’C operating temperature range when decoding HD content
In a nut shell; silent operation at the expense of running the GPU 10 to 15 degrees hotter than before. It may lessen the card’s life but my HTPC is almost silent now.

Review: bequiet! 300W TFX Power Supply Unit BN136 Upgrade for Dell Studio 540s

Review: bequiet! 300W TFX Power Supply Unit BN136 Upgrade for Dell Studio 540s


The be quiet 300W TFX BN136 power supply unit fits nicely in a Dell Studio 540s and has ample power on it’s dual 12V rails to power an ASUS 1GB GeForce GT430 PCI graphics card with ease. It was not found wanting under the FurMark 15 minute stress test; one of the toughest tests for a power supply and graphics card to endure.

The power supply itself is a beautiful item and oozes quality with it’s enamel-black finish and it’s braided-quality cables.

The bequiet! 300W TFX BN136 power supply unit is packaged with a euro-type electrical cable, so you will have to consider an adapter or alternative cabling if your live in the UK.

It has only two SATA electrical connectors – daisy-chained together – intended for connecting a pair of drives stacked together. You will need more than this. A Molex to SATA connector needs to be factored in with your purchase.

The bequiet! 300W TFX BN136 power supply does not break any records in terms of operating quietly. It’s noise levels are slightly louder than those from the Dell’s original power supply unit. I would say it’s acceptable for general use but my machine is a dedicated Home Theatre PC, where quiet operation is essential. It’s certainly the noisiest item in my machine. Ironically then, it lives up to it’s name:

Shsh! Be Quiet!


Last year I purchased an EZCool 400W TFX Power Supply Unit as part of an upgrade I was doing to my Dell Studio 540s to replace its original Liteon 250W psu. I needed a more powerful supply to fuel an ASUS 1GB GeForce GT430 PCI graphics card I was installing as part of that upgrade. The new graphics card required a maximum of 18A on the 12V rail. The Liteon fell short of that but the beefier EZCool could deliver that with ease.

I disliked the EZCool 400W TFX psu because of the noise it produced. It was absolutely no good for use inside a media centre. Noise levels were too high. See my Amazon review here: EZCool 400W TFX PSU Review: Tim Wolverson

Recently, the EZCool 400W TFX psu died a smelly, electrical death and I was forced to start looking for a replacement. What I found was that the range of TFX power supply units was still very limited in the UK, particularly if you want one with an output greater 300W. Yes, it’s possible to ship good quality ones in from the States but the hefty shipping charges were too lofty for me; almost as much as the items themselves. So I started looking deeper into the subject of power supply units by seeking help on a number of forums. I certainly didn’t want to buy another EZCool 400W TFX psu. I’d had a guts-full of those.

I eventually started gravitating towards the bequiet! 300W TFX BN136 power supply unit as a favourite contender. bequiet! 300W TFX BN136 PSU

German engineering; energy efficient; boasting whisper-quiet performance; quality components; made to last with superior reliability. A best seller. And the more I began to understand the internals of modern power supply units, the more this item appealed to me, despite its lowly 300W output tag. I had discovered that a power supply’s output wattage was not the crucial factor in power supply selection. The total continuous current on the 12V rail(s) is the most important.

The manufacturer’s website offers an array of technical data on this unit. In terms of output, success or failure for me depended on one key attribute, the available current on the 12V rail to ensure a consistent supply of power to the graphics card’s GPU; 18A at 12V = 216W.

The bequiet 300W TFX BN136 psu has dual 12V rails and the maximum current of each rail is listed as:-

12V (1) – 14A
12V (2) – 16A

At first glance, the maximum current on each rail may lead you to conclude that neither rail can supply the 18A required for the ASUS 1GB GeForce GT430 PCI graphics card, or the sum of the currents totals 30A, meaning that there’s plenty of combined power on tap with some to spare. Neither assertion is correct.

If you look down the list of technical output data on the manufacturer’s website, you will find a rating:-

Max. Combined power 12V  =  250W

This means that the combined maximum current is 250W divided by 12V = 20.8A

So I know that this unit is capable of delivering the power required to my graphics card.

So why have dual rails instead of a single one? The simple answer is safety. Having too much current available on one rail could result in fire if there was an electrical short. There is also a risk of electrocution with high currents, even if the voltage is relatively low. It’s much safer to split the power and transmit it through more than one rail (pair of wires). Some power supplies with greater wattage have multiple 12V rails to keep everything safe. More details can be found in the relevant forums.

After checking other important technical data, like physical size, I ordered the bequiet! 300W TFX BN136 psu from Amazon.

Review: bequiet! 300W TFX Power Supply Unit BN136 in a Dell Studio 540s

1.     Packaging & What You Get in the Box.

The bequiet! 300W TFX power supply unit BN136 is supplied vacuum packed in a swish, black, cardboard box. The box boasts the unit’s features on the front, its technical details on the back and its awards won on the top.

The box lid was security-sealed, which I like very much. A good start.

The first thing I saw on opening the box was a euro-plug power lead for the power supply. I live in the UK, Amazon! It’s no good to me without an adapter! So that was a negative for me. Not a big one because I knew I could use the power lead I already had. But what if this were not purchased as a replacement or upgrade? What if it were purchased to build my own computer from scratch? Yes, I’d have to bear the cost and more importantly, the inconvenience of having to buy a compatible power lead.

The very least Amazon could do here, is throw in an adapter so everything can work straight out of the box or make it clear that this is what to expect.

The power supply is wrapped in bubble-wrap and the electrical cables are fastened together with an elastic band. There is a multi-language manual and a small bag of cable ties and black screws to secure the power supply in your machine should you be building a PC from nothing. A very well packaged item, with little chance of the unit getting scratched during transit.

With the psu free of its sheathing, you begin to feel what an excellent piece of kit this is. The weight of the unit suggests quality; the enameled black coating of the unit looks great; the quality of the braided cables is second to none. From every angle, the bequiet! 300W TFX power supply unit BN136 oozes quality and aesthetics.

2.       Fitting the bequiet! 300W TFC Power Supply Unit in a Dell Studio 540s

After the failure of my EZCool 400W TFX power supply, I replaced it with the original Liteon 250W power supply that came with my machine; just to keep the media centre alive until the bequiet! 300W TFX BN136 psu arrived. It worked to a fashion. It was adequate in enabling the continuation of recordings. Its under-powered output though manifested itself in occasional bouts of severe ‘stalling’ when watching even standard definition video; sound and video stutter, lasting for seconds.

I was certainly eager to swap power supplies the moment the bequiet! 300W TFX BN136 psu arrived.

I removed the Dell’s original power supply by removing the case lid; the fastening screws at the rear of the unit and all the electrical connections to the motherboard and internal hardware.

The bequiet! 300W TFX power supply unit BN136 slides back onto, and engages with the Dell’s case-lug nicely to secure the unit at one end. I used three of the supplied black screws to secure the power supply to the chassis of the Dell 540s. The screw holes aligned perfectly and the unit was fixed solidly with the screws tightened.

I then proceeded to connect up the power cables. The CPU power cable was long enough to reach the connection point on the Dell 540s motherboard. There was enough length to route the cable around motherboard heat sinks and the graphics card to make a neat job of it. I had read reviews elsewhere that this cable was not long enough in some cases. All I can say is that it was of ample length to fit in the Dell 540s. As a comparison, it was equally as long as the CPU power cable of the original Dell psu.

I then proceeded to connect main power to the motherboard. The bequiet! 300W TFX psu BN136 is equipped with 20-pin and 4-pin motherboard connectors that can be combined to make the 24-pin connection for the Dell 540s. I had to remove the front fascia of the PC and push the DVD ROM forward to gain access to the motherboard connector.

Connection then was simple. I slid the DVD ROM back into place. Conveniently, the braided part of the motherboard cable terminates some distance before the plug. This makes it easier to fold the wires flat underneath the DVD ROM where there isn’t much space.

More than likely, you will need to purchase a molex to Sata power adapter to increase the number of available Sata power connectors to four.

The bequiet! 300W TFX power supply has only two Sata power connectors daisy-chained on the same braided cable. In the Dell 540s, the HDD is mounted some distance away from the DVD ROM, and at right angles. This cable alone then is not physically capable of supplying power to both devices. I used this cable to connect up my SSD & HDD which are situated one on top of the other. The distance between connectors was ample.

I used the molex to Sata adaptor to supply power to my DVD ROM.

I tucked the braided cable into the integral cable tidy inside the Dell’s chassis and boxed the machine back up.

3.      Conclusion

The bequiet! 300W TFX psu is not as quiet as it’s name would suggest. I’ve been listening to it’s fan noise over the course of a week now. I would say that it is a fraction louder than the original Dell psu. Not by much, but I’m disappointed that it is not any quieter. It’s in a Home Theatre PC after all and that’s what it is being judged on. It will do. But only just.

There a four fans in my Dell 540s. This is the loudest thing in there by far. And it runs continuously. By contrast, the case fan, CPU fan and graphics card fan are all whisper-quiet.

Seemingly, there is ample power for the ASUS 1GB GeForce GT430 PCI graphics card, a Blu-Ray ROM drive, HDD, SSD, dual core processors and a dual TV tuner card. The graphics card plays High Definition video content flawlessly.

I ran the 15 minute FurMark GPU stress test, keeping a close-eye on GPU temperature.
The test was successful in that the GPU on my card did not burn out and there were no stability problems caused by a lack of unsustainable power.

In Hindsight

I strongly believe that I should have expanded my choice of power supplies by purchasing a regular sized PC case; swapping everything over and seeking out a normal factor, uber-quiet power supply.

If the bequiet! 300W TFX psu had been a little quieter than the original Dell psu, I would have been very happy with its purchase, since it satisfied the power requirements of my hardware.

My Scores

  • Product Quality: 5/5 (A very well made unit; excellent quality braided cables)
  • Value for Money: 4/5 (Had to purchase molex to SATA power connector. Came with euro-plug)
  • Performance: 3/5 (Too noisey for my liking and marked down because of it’s misleading name)


Thanks for all the help at the forums.
My thread on those forums: Candidate TFX PSU for Dell 540s and Asus GT430
My concise review on Amazon UK