CPU goes berserk

I know, this is probably a problem I would post in some computer hardware forum somewhere. But I figure, since some of you - like me - are trying to build the ultimate studio PC, maybe someone has crossed over this problem before.

Hardware:
Intel S5500HCV server board, 2 x Xeon E5620 (8 cores each), 8GB unbuffered RAM (used to have 16GB buffered but troubleshooted that away), 120GB Corsair Force3 SSD, 4 x Seagate Constellation 1TB in raid10 (for storage), MOTU 8pre USB2 (with driver 4.0.5.9644, just bought this card before xmas). Temp (measured with speedfan on all points) maximum 45 degrees. Newly installed Windows 7 x64 with bare minimum (chipset drivers, speedfan and Cubase7LE).

Problem:
I have all this performance, but something is way off. Every 2 seconds, cursor / bars / windows / actually the entire OS is halted for half a second. Enough to be a problem. When playing Spotify or any kind of sound, all sound stops for half a second every 2 seconds. When recording a simple audio track with no effects whatsoever, same thing. If I run youtube, videos act the same. Whatever I do, the computer pauses for half a second every 2 seconds. Such simple thing as scrolling a website even pauses the same way.

Troubleshooting:
Used to have Win on RAID5 volume, installed SSD, problem remains. Exchanged RAM from RDIMM to UDIMM, problem remains. Installed Xp just for the fun of it, problem remains. Did a trial install of Win7x64 volume license, problem remains.

What the hell is happening? This hardware used to be a VMware server for a company that I swapped out after 2 years, and it’s never ever acted this way when installed at customer. I’ve got all this juice and still a damn irritating problem. Someone please give me a clue :confused:

Ok can close this now… Obviously there was some hardware issue, and I found it with some googling;

Appeared to be the NIC’s. Disabled them in BIOS and installed a spare realtek NIC I had… voila! Everything rund smooth as **** right now. CPU’s at 0-1%, no stuttering, just pure performance :slight_smile: