I forgot to attach the rest of the stuff, so I'll do it here.

Desktop
Windows 8.0
i5 - 3570k overlocked to 4.4ghz stable
16gb ram.
Operating speed seems pretty constant in CPU-Z, but I cant say for sure.
When the issues resolves itself, it doesnt seem to be triggered by anything we do. Last night ...

We have been having this issue lately playing multiplayer where after I join my game has super low FPS, jumps and buffer rapidly increasing. Typically, this happens when the client can not keep up with the server.

However, seemingly for no reason, this stops at random, and everything plays normally ...