Is this noise normal for a MoBo ? (ITX: Asus z170i Pro Gaming)

Hi everybody,

I just upgraded my rig to skylake, but my new mobo (Asus' value ITX motherboard: the z170i Pro Gaming), but it seems to make an unusual noise (that my previous mobo didn't):

Noise Recording on iPhone

As this looked very similar to coil whine, I tested the Mobo outside of the case without RAM or GPU and with the PSU far on the side. There is a constant hum from boot that doesn't go away, but it wouldn't be much of an issue as it would get drowned by the ambient noise of the room. What is more bothersome is the occasional crackling/sizzling that you can here at the start or around 0:18 and 0:43.

Is that normal behavior ? Were my old MoBos just particularly quiet ? If not do you think I should ask for a RMA, and if so, should I go through Amazon or Asus directly ?

Thanks in advance for any help you could provide !

I have the same problem with this particular board, and I did RMA it once with Newegg (which did not fix the issue). There is also a review which mentions it there. ASUS support said it's probably not normal and tried having me adjust some BIOS settings. Nothing has made it any better. I haven't had any issues with the board beyond the sound, however.

Since you purchased it from Amazon and they only started selling it in the past couple of weeks, it seems like it could be an issue with all of them at the moment.

Sounds normal to me. Turn off any C-states and spread spectrum settings and see if it changes (many boards make hissing/buzzing sounds with C6 especially). Motherboards aren't silent, you just generally have enough other ambient noise to not notice any of the sounds they make.

Ok, thanks for the feedback. So you both don't think I should RMA, it is expected behavior for the board ? (It just a bit unusual, I never had a board that made noise before ^^)

ps: isn't C-state only for Sleep, Hibernate, etc ? It shouldn't change while the pc is running no? I never put the PC to sleep of Hibernate since on SSD windows wake up in 5 sec.

Anshur said:

Ok, thanks for the feedback. So you both don't think I should RMA, it is expected behavior for the board ? (It just a bit unusual, I never had a board that made noise before ^^)

ps: isn't C-state only for Sleep, Hibernate, etc ? It shouldn't change while the pc is running no? I never put the PC to sleep of Hibernate since on SSD windows wake up in 5 sec.

Click to expand...

C-states are idle or power saving states, with the exception of C0 which is a fully active CPU. All variations of a power state while still executing instructions are called P-states. The rest of the C-states from C1/C1E down to C6 are either idle (halt) or sleep/power down. These are software controlled to allow the OS doing the scheduling to have maximum flexibility on CPU usage vs power consumption. Sometimes limiting the idle modes will prevent the louder coil whine because they can occur when the CPU is in a low power mode or transition.

I've never had a board that was fully silent, once you run them on a test bench with few or no fans you will start to notice all the crazy electronic sounds they make. Mouse movement is a big culprit for whining. You have several controllers and power supplies all over the board doing various things, some electronic noise is normal. If it is very aggressive and annoying, by all means RMA it. Only you can decide if it bothers you enough to get a different one, especially with no guarantee the new one will be better (things like power supply choice can effect it as well).