cpu causing hum?

[Arsenu,]

seems like im having some extra luck lately...

anyway, iv'e noticed something very strange that had never occurred to me before until very recently, and i cannot recall any change that has lead to this

basically, every time i do anything that requires CPU usage, there's a noise/hum coming from me speakers, as if my speakers are "listening" to my CPU...
when google maps is on, every time i move the map i hear a small "click" thats not supposed to be there. but so far for non DAW related stuff...
when using a DAW (either cubase or PT) there's always some hum going through the speakers (when not playing anything), and when i turn on a plugin, the hum get's a bit louder (still, not playing anything, nothing is plugged in)

the hum is not THAT bad, and does not appear to be audible on any output/input anywhere, so it doesn't get in the way of my workflow.
but it is fucking annoying...

now, what iv'e realized is that when i open "playback engine" under "setup" tab on Pro Tools 10, and lower my "host processor" from 4 processors to 2, the hum goes away! which makes the problem obvious...

thing is, i am now forced to work with only 2 processors instead of 4, and i have NO IDEA how to treat this problem!
it has nothing to do with hardware, electricity or audio connections, it's obviously some moronic option that is turned on/off somewhere and should not be.

does anyone have a clue? i really don't know even where to start...

 

[sprack]

What kind of interface are you running through?

 

[Mutant]

The "hum" from a modern CPU would be in Gigahertz range, so obviously inaudible.

My guess would be that when you are using 4 cores, the power consumption increases and this puts a strain on your power supply unit which somehow starts to send a dirty power to your soundcard/interface.

 

[Arsenu,]

im running win 7/64 bit through a MOTU traveler

 

[kev]

I spent a few days trying to figure this out, so you are in luck. It is speed step technology (or similar if you are using AMD). Disable speed step or EIST i think in your bios to keep you cpu at constant speed, rather than allowing it to power save.

 

[Arsenu,]

^ awesome mate! thanks a LOT!

do you mind explaining tough where can i find that speed step thing? is it only the BIOS or should i look for it in the device manger/control panel?

 

[sprack]

Speedstep (p-states) are usually in the OS. Setting the power profile to High Performance will keep it at max p-state. Generally p-states are not an issue since the processor can and does do them independent of the OS.

C-state cause latency and huge power spikes/drops, the happen on a 200microsecond or less basis. Those have to be disabled in BIOS. Turbo mode uses C-states as a way to clear coherency issues before parking cores and bumping up.

If your power supply is supplying that noisy a power its usually one of 2 things, bad grounding or noisy caps.

 

[::XeS::]

Disabling C1E you will cut lot of noise from the speakers but you can try other Power saving features to see if something change. With C1E enabled you can hear lot of bad noises when the cpu works.

 

[kev]

Yep, C1E also needs to go. You can find it all in your bios settings. I'd always prefer to remove the feature directly in the bios rather than rely on a OS implementation, but whatever gets the job done for you.

 

[TomMartin]

I had this problem. A new motherboard fixed it.

 

[kev]

All gigabyte motherboards seem to be prone to a lot of EMI.

 

[Arsenu,]

EIST disabled and..... it works!
welcome back my beloved quad-core!!!

cheers guys! thanks for the help! that problem was so weird i thought no one is going to have a clue!

:Smokin::Smokin::Smokin:

 

[TomMartin]

All gigabyte motherboards seem to be prone to a lot of EMI.

Funny you mention. My noisy board was gigabyte, switched to asus and it's silent.