Funny whirring sound when running off battery (MBP)?

[Max on Macs]

Hi guys,

I don't think this is the whining people keep talking about, but it could be. When running on mains power my laptop is almost silent, except for the occassional noise from the hard drive and if you are in a completely silent room and put your ear against the metal you can hear a fan too. So, quieter than my PowerBook G4 and quieter than any PC laptop I've ever seen, een near or used. When running off battery however it's another story. As soon as I take the magsafe out it starts making a funny whirring sound, which stops for a second or two occasionally, but when I put the magsafe back in it goes off almost immediately. Any idea what this is?

Thanks

 

[bpd115]

does it go away when opening photobooth?

If so, welcome to the club.

 

[jsw123]

does it go away when opening photobooth?

If so, welcome to the club.

I have the whirring problem and just opening photobooth and it went away.
Thats absurd. I like photobooth though, so I think ill just leave it on all the time.

 

[Max on Macs]

Yes opening PhotoBooth gets rid of the problem...until I close it. How weird. Do you think Apple will do something about this? I called up my local reseller and they said they can run the Apple diagnostics on it but if it doesn't have anything wrong with it they'll charge £80 for that and even more to fix it! They claim Apple forces them to do this.

 

[NJuul]

Think it's because of the two cores...
I have this too, but when I turn off one core using CHUD, the whining goes away completely

 

[indigoflowAS]

I have learned that opening comic view and closing it will get rid of the whine for quite a while...but we should not have to do that every time we wake it from sleep.

not sure if it will work for everyone, give that a shot...that way you chew through less ram.

 

[bpd115]

There is a reaaaally long thread on the apple support forums.

It's related to power draw.

Mirror widget makes it go away
photoboot does too
bluetooth devices etc..

but reduce your battery life.

 

[jsw123]

Think it's because of the two cores...
I have this too, but when I turn off one core using CHUD, the whining goes away completely

You are absolutely right. However, turning off a core kindof defeats the whole purpose of the dual core system (a.k.a. why we paid such a premium)