windows 7 - What is this HDD noise so low it's only detectable at night?

08
2014-07
  • naxa

    My HDD that seems not be writing anything is giving a low, continous, repetitive, systematic noise pattern. It's so low I can only hear it at night. It goes away after some time. Comes several times a night.

    I'm pretty sure it's the HDD since, well, it has a very HDD-like sound, like it's doing some low-noise diagnostics or something. Also, my computer is pretty silent otherwise, and I'm not doing anything CPU heavy, my utilization at these times is <10%.

    edit I think the drive is 'idle' because if I do anything non-cached the sound disrupts, however if I only do cached reads it's not. But I've also done some copies of small files I've recently edited and the noise didn't go away. Still, it always go away if I enter a directory what I didn't visit since startup.

    But spinning up or writing are usually very different and more noisy from what I hear, because they are not that repetitive. The one I hear is cyclic, after some time it dies off. I've run handle as administrator on the singular and non-system partition the HDD has, E: (my only other drive C: is an SSD):

    C:\Users\-->handle e:

Handle v3.46
Copyright (C) 1997-2011 Mark Russinovich
Sysinternals - www.sysinternals.com

System             pid: 4      type: File            50: E:\$Extend\$RmMetadata\$TxfLog\$TxfLogContainer00000000000000000001
System             pid: 4      type: File            6C: E:\$Extend\$RmMetadata\$TxfLog\$TxfLogContainer00000000000000000002
System             pid: 4      type: File           108: E:\$Extend\$RmMetadata\$Txf
System             pid: 4      type: File           130: E:\$Extend\$RmMetadata\$TxfLog\$TxfLog.blf
System             pid: 4      type: File           D54: E:
svchost.exe        pid: 940    type: File           31C: E:
svchost.exe        pid: 940    type: File           43C: E:\System Volume Information\tracking.log
svchost.exe        pid: 940    type: File           44C: E:\$Extend\$ObjId
svchost.exe        pid: 2884   type: File           490: E:\--\handle.exe
svchost.exe        pid: 2884   type: File           6A8: E:\--\handle.exe

    edit not a proof, but I usually assume that no write happens when I hear the strange repetitive noise. I sometimes hear the drive spin up after I hear the strange noise (usually after I access some non-cached directory), and the sound of writing large files is very different (not this repetitive and systematic but fairly random).

    What could be the origin of this sound?

    • Answers
  • naxa

    After asking I suddenly realized the suspicion that it may be some seeking noise. I could only find this trial/shareware program HD Tune Pro to test it (no affiliation; but the free version has no tests).

    It has separate tests containing seek tests in the "extra tests" tab. I've tried all of them one by one. The sound I hear seems to be tested by Sequential outer / Read - only my does it longer than the test. (I don't know practically anything about HDD hardware yet so I'm not sure what does this test do.) Why my system does this on its own is a question that remains. :)


    • Related Question

    cpu - Processor noise. What generates it?
  • Stefano Borini

    So, I am probably not alone in noticing that any processor makes a high pitch buzzing sound while working, and this sound is more noticeable and varied in pitch when computations are performed. I also hear it from the GPU when doing operations like dragging a window around. It's not the fan. I also recall a group of hackers at some badass convention recording this noise while gnupg created a key, and got some information about it.

    Here it is: Acoustic cryptanalysis

    What physical phenomenon produces this sound?

    Here are some other reports

    http://www.videohelp.com/forum/archive/buziing-noise-from-processor-t369398.html

    https://www.rohitab.com/discuss/lofiversion/index.php/t11499.html


    • Related Answers
  • Fred Hamilton

    The most common audible noise coming from computers (besides fan noise, of course) is from the transformers used in the power supplies. They are switched at very high frequencies and they generate a powerful magnetic field (that's how they couple energy from one side of the transformer to the other). That powerful magnetic field is essentially a big electromagnet, so any ferromagnetic material in the vicinity will be pulled towards the transformer and pushed away from the transformer thousands of times a second. Most things are soldered down, but some things (like the windings of the transformer themselves) can have a little play, so they move back and forth at the switching frequency (or a harmonic or sub-harmonic of the switching frequency). This is the most common source of physical noise, and it can be modulated by the load on the CPU (as the current draw from the CPU changes, the magnetic field intensity and duty cycle changes). However the most common source of this kind of noise in this environment is the transformers (sometimes called inverters) used to create the high voltages for the backlight of LCD monitors and TVs.

    Since this seems to be a popular topic, I'll add a note on the other big source of noise in PCs. The noise discussed above is produced mechanically, you can hear it without any soundcards or speakers. If you're talking about noise you hear through your speakers, there's another source. CPUs and GPUs use 10s of amps of current from the power supplies, and that current varies depending on what the CPU/GPU is doing. The power supplies typically use the same ground return (usually a copper ground plane layer in the motherboard PCB) that all the other chips (including audio) use. Ohm's law says Voltage (V) = current (I) times resistance (R). An ideal ground plane (made of an ideal conductor) would be zero ohms from any point to any other point, so even 100A of current wouldn't generate a voltage (100 A * 0 ohms = 0 V). But a real-world copper ground plane has some resistance, say 0.010 ohms from one end to the other. So if the CPU current switches between 30A and 10A, the voltage across the ground plane may vary between 0.3V and 0.1V. This means that the ground the audio IC is relying on to "stay still" is actually moving up and down by 200mV. That makes the audio output of the IC jump up and down by up to 200mV (depending on what the processor is doing). Which you hear as noise.

    This is a very, very simplified example - people have written books about this topic. I'm just trying to convey the basic mechanism.

  • bobobobo

    The Toshiba m40 laptop also used to make this insanely annoying squealing noise. If you plugged in a USB key, the noise stopped.

    From here, someone writes about that squealing problem's cause:

    The problem is relating to a capacitor that is vibrating probably because there's too much power flowing through it