Question regarding CPU and Memory Speed Limits

[aznriptide859]

My friend has been complaining about a build for some time - seems like he's running into more problems nowadays than he was in the past. He complains of user lag (I'm guessing programs freezing/crashing often or something - he claims especially Google Chrome or when he's multitasking with programs/browser tabs) and that it's happening since he build his machine.

I looked into his CPU (Intel i7-930) and his memory (Corsair 3 x 2GB DDR3-1333), and on Intel's site it says his RAM is limited to only DDR3-800 to DDR3-1066. Now I've been building computers for years, and excuse my noobness but I had no idea CPU's had memory speed limits. That brings up a few questions;

1. Is this mismatched issue what's causing his user lag/program crashes?
2. Is there any way of fixing this, sans replacing his RAM completely?

As a future reference to me, how do overclockers get their higher RAM speeds to match with the CPU, if they have speed limits? I even looked at Intel's newer Sandy Bridge CPU's, and they seem limited to just 1333Mhz. Is there something you have to adjust with the CPU/BIOS?

Thank you for your time, and excuse the (possibly) noob questions

 

[k1114]

Those are not speed limits, they are the stock speed. But if he was not experiencing the issue before I would think his first step would be a virus scan, defrag, deleting bloat, updating drivers, etc, stuff with windows.