Hi, I hope I'm posting in the right section.

I have 2x1GB Corsair XMS2 2048 PC6400 in my system timed at 4-4-4-12 2.1v. It gets the job done....but I also want to overclock my CPU further. It's an e6420 and currently it's clocked at 3.2Ghz. My motherboard is the hybrid 650i from Asus (P5N32-E SLI Plus).

I've upped the voltage of my vcore to 1.4, HT to 1.35, NB to 1.5, SB at 1.5, LDT to x4, spread spectrums all off. I'm running FSB unlinked at 1600 and RAM at default 800 for a 1:1 setup.

I cannot go any higher. The system will not even POST unless I take the FSB back down to 1600 (400).

I'm still fairly new to the OC game and I advice and or opinions from you, the enthusiast community. Is the RAM holding me back? Shall I loosen the timings to say 5-5-5-18, keep the voltage 2.1v and upp the freq. on the RAM? If that is indeed what I should try, shall I try to keep it at 1:1? I have heard of people saying that my memory can go up to 1000Mhz easy on loose timings but that's from the reviewers on Newegg.com Please advise! Thanks.

You're saying that ur not able to overclock the FSB above 400Mhz, and this is ironically also the exact speed of ur RAM?

Well, the 6400C4 from Corsair SUCK, but they will overclock somewhat, and i doubt that the motherboard is holding u back because the 650i SLi northbridge chipset is much more stable than the 680i SLi.

Try loosening the timings to CL5 and overclock the RAM along with the FSB.

The price was right and the rebate made the sticks even more appealing so I bit. Anyway, sorry if I seem to let things go over my head but I didn't make the connection between the FSB and RAM speeds. Anyway, I mildly overclocked the RAM to 425 and I'm now hitting 3.4Ghz. I'm running Orthos and it just passed the 1 hour mark.

I'm still learning the ropes of overclocking. I did overclock an Opteron 165 to 2.7 stable but that was the extent of my OC'ing experience. I've never been much of a book learner so I just dove right into OC'ing my new rig. Now, I'm pretty satisfied with the results...until the bug bites again.

Oh, and I DID loosen the timing to 5-5-5-12 1T and kept the voltage at 2.1.

Dont worry, the best knowledge in PC Hardware comes from experience.. not to mention enjoyment!

The 650i SLi can go beyond 500Mhz, so dont be too afraid to raise the voltage to 2.2 or even 2.3, but take it one step at a time.

Will do, thanks for the encouragement Track.