Hmm... I tried setting the clock to 6x but leave the voltage at 1.3 and it still did it. When I set the voltage above is when it starts happening.
I think I'm going to pull out the pinmod, and see if the same thing happens with just the chip. If it doesn't, I'm going to switch to the other VSS. If that doesn't work, I'll try doing it with something other than copper.
I have the same problem. I thought it was my graphics card at first because in safe mode it didn't start making the noise. I had Dell replace it but there was no luck there, it has to be some other component in the system.
Try booting up in safe mode and see if the problem is still there and then figure out what components are inactive with safe mode and test each one out by disabling them and rebooting.
I seem to remember people having similar noise problems with the i8600 notebook and it turned out it was something with the USB. You could try disabling the USB and see if that makes it go away. I think there is more info in the FAQ thread in Dell General. Go to the i8600 specific link.