Help with my recent i7 Build

[mogwai]

I have over the past few months been putting a new rig based on spec below:

Intel Core i7 920
Corsair H50-1
6GB PC-12800 Corsair C7
Gigabyte EX58-UD5
Crucial C300 256 Gb
Highpoint Rocket 620 Sata III Controller
Zotac GTX 280 1024 MB
Asus Xonar DX
Be Quiet! Dark Power Pro 550W
Windows 7 Pro 64 Bit

Today I have put windows onto it and as soon as I plugged in a USB flash drive I started to get a buzzing sound. I then tried a spare psu that I had and the noise went away. However I have just installed Crysis and also carried out the Windows Performance Index assessment, I now get a noise from the psu when either are run.

This is the second UD5 I have had that does this. I have had it too long to be able to switch to a different make. However as I am getting strange noises after switching PSU's it leads me to believe that the UD5 is the problem. Do you guys agree?

I have turned off the C1E option in the BIOS as I have seen some suggestions this can cause this noise.

I am inclined to switch back to an Asus board. Would the P6T SE be sufficient if I don't want SLI or Crossfire? The only thing I am thinking of doing is to OC the CPU to 4 Ghz if I can.

For the above spec and the OC to 4Ghz is a 550w PSU sufficient?

 

[RJC]

Switch off EIST & C1E see if that helps.

 

[mogwai]

Thanks for the suggestion I have already got both of those disabled.

 

[mogwai]

Seems to be related to load. As when I swap my Gtx 280 for an 8400 GS I don't get the issue qith either psu. Do I just need a PSU with more power e.g. a 650w? if so is 650w enough?

 

[CAPTAINBUMFLUFF]

I have a similar problem with my corsair hx 650 exact same problem some days it feels like making the noise somedays not I have a very similar build to u