iMac high frequency noise (21.5" late 2012)

[Bazzzle]

hello,

there is a quiet noise coming from the top right of my iMac, and i have diagnosed it as the C3 idle noise problem. This is the second iMac (after getting the first one replaced) to have this issue.

Specs are:

• i7 QC
• 650M
• 16GB RAM
• Fusion Drive

now i would go ahead and get it replaced again, but it is pretty quiet and the replacement would probably have the same issue anyway...

so i'm just wondering if there are any imacs out there that don't have this noise? (at all)...

i'm also wondering if it is any indication of a problem with my processor (i.e its breaking... or something?).

thanks in advance!

 

[WilliamG]

It is as you've described - the C3 idle noise. There's not much to do about it, and it doesn't hurt your system at all. There are ways to keep the processor out of idle state, and therefore eliminate the noise, but then your CPU temps remain higher. I suggest doing a Macrumors search and you'll find numerous threads on this.

 

[Bazzzle]

It is as you've described - the C3 idle noise. There's not much to do about it, and it doesn't hurt your system at all. There are ways to keep the processor out of idle state, and therefore eliminate the noise, but then your CPU temps remain higher. I suggest doing a Macrumors search and you'll find numerous threads on this.

Thanks for the reply,

I'm going to try to ignore it, i only noticed it because i was typing an essay up in the early hours of the morning, when it was silent!

I'll have my external hhd plugged in and on for time machine backups anyway, and that sounds like a jet haha

 

[WilliamG]

Thanks for the reply,

I'm going to try to ignore it, i only noticed it because i was typing an essay up in the early hours of the morning, when it was silent!

I'll have my external hhd plugged in and on for time machine backups anyway, and that sounds like a jet haha

Yeah you only tend to hear it when there's nothing going on, and it can drive you a bit bonkers. I have a top-of-the-line Sony Vaio Z2 (cost $2,500 in mid-2011), and the C3 IDLE sound drives me absolutely batty when the room I'm in is silent.

This is why I sleep with a fan on at night. I get driven bananas by all kinds of weird sounds so a fan drowns them out.

 

[bmcgrath]

Strange.

I hear this C3 state from my HP desktop in work. On my mid 2011 iMac I don't hear it at all even if I put my ear on the top or back of the machine. I just hear the fans and HDD whirring quietly.

 

[Bazzzle]

Strange.

I hear this C3 state from my HP desktop in work. On my mid 2011 iMac I don't hear it at all even if I put my ear on the top or back of the machine. I just hear the fans and HDD whirring quietly.

Guess its just the luck of the draw!

that's why i got my first one replaced, hoping the new one wouldn't have it... don't want to go through the hassle again so i'm going to try to ignore it...

 

[bmcgrath]

Guess its just the luck of the draw!

that's why i got my first one replaced, hoping the new one wouldn't have it... don't want to go through the hassle again so i'm going to try to ignore it...

Something that does bother me with my Macbook Pro is that I cannot hear it on that machine until I plug in a set of external speakers and then I hear this whiney high pitch noise I believe is related to the C3 power state. As soon as I play a HD video on the machine the sound goes away even on mute.

ANNOYING

 

[Bazzzle]

Something that does bother me with my Macbook Pro is that I cannot hear it on that machine until I plug in a set of external speakers and then I hear this whiney high pitch noise I believe is related to the C3 power state. As soon as I play a HD video on the machine the sound goes away even on mute.

ANNOYING

i've been getting this noise from my bose speakers for a couple of years now, always put it down to the crappy £0.50 audio cable im using...

 

[bmcgrath]

i've been getting this noise from my bose speakers for a couple of years now, always put it down to the crappy £0.50 audio cable im using...

I think I ruled out the cable situation as I spent money on some decent shielded gold cable. It did help but didn't eliminate entirely!