My new computer makes a noise like a hard disk being accessed - not very loud, and rattling or maybe hissing. The noise changes when I do different things. It is somewhat load dependent - on Windows 7 when the system is completely idle, it's almost gone. With a different operating system, it's there all the time. If I scroll a web page, it is noticable. It gets a bit worse when I do something CPU or IO intensive. The crazy thing is, when I open a terminal window on this PC, log in to a server via SSH, and do something computing intensive there, it also gets loud, although my CPU is barely utilized. Just the updating of the screen alone causes the noise. When I run a game, or a benchmark, it's almost gone.
At first I thought it was the hard disk, but the PC makes the same noise even with the hard disk removed (booting from SSD, or optical drive)! It sounds like it's coming from the power supply or the mainboard. It could be from the electronics, or from the fans.
Mainboard: MSI P67A-C43 B3 CPU: Intel Core i5-2500 Graphics: XFX Radeon HD 6870
I never have any crashes, and the temperature seems to be OK all the time. What could it be? Could my PSU be underpowered? Are there any BIOS settings that might help?
(My crazy theory at the moment is that the amount of power that the PC is using at any moment changes rapidly (because the CPU is going in and out of low power states like 100 times a second). That changes the load on the PSU, which changes the fan speed rythmically and creates the noise. That would explain why terminal windows cause the noise, but not games. I don't know if that's plausible or not...)