Can CPU limit FSB overclock?

D

Dew itt right

2[H]4U
Joined
Oct 28, 2005
Messages
3,314
Even if you crank down the CPU multiplier, can the CPU still limit your FSB overclock? I had an EVGA 680i LT with my current E6750 and no matter what I set the RAM and CPU down to, the board wouldn't even POST with a FSB over 440MHz. I have since upgraded to an XFX 680i board and I still can't post over 440MHz! So either both of these boards have the exact same FSB ceiling, or the CPU (or perhaps something else?) is limiting the FSB. I've tried at 1.4v and 1.5v FSB voltage and the chipset is watercooled. System is in the sig.


For example, everything runs fine at 438MHz FSB, 3504MHz CPU (438x8), RAM unlinked at 1066MHz. But if I try raising the FSB to 450MHz, dropping the CPU multi down to 7 (7x450=3150MHz) and dropping the RAM down to 900MHz (unlinked or linked & sync'd), it won't boot. I've also tried leaving the RAM at 1066MHz unlinked and nothing changes.


Any suggestions?
 
Dew itt right said:
Even if you crank down the CPU multiplier, can the CPU still limit your FSB overclock? I had an EVGA 680i LT with my current E6750 and no matter what I set the RAM and CPU down to, the board wouldn't even POST with a FSB over 440MHz. I have since upgraded to an XFX 680i board and I still can't post over 440MHz! So either both of these boards have the exact same FSB ceiling, or the CPU (or perhaps something else?) is limiting the FSB. I've tried at 1.4v and 1.5v FSB voltage and the chipset is watercooled. System is in the sig. Any suggestions?
Click to expand...

I think certainly the CPU is the deciding factor. Some are just duds...nothing you can do about a good or bad draw. Now that you've eliminated the chipset itself (2 different motherboards), all of it rests on the CPU.

E.g. I've had old school AMD chips that would benefit more from high multiplier vs. FSB b/c I knew the CPU and motherboard couldn't handle it. Now that you know your motherboard isn't the cause, I don't think there's much less to do except more voltage -_-
 
Well, I have another proc on the way that should definitly solve this problem. The guy with the highest clocking E6300 in [H]'s C2D OC database was selling his CPU so I snatched it up. It's CPUz validated & prime stable at 550MHz FSB (3.85GHz) so needless to say there's no way this CPU will be the component holding back my FSB. He's actually gt it to load XP at 4.0GHz but it wasn't Prime stable. It won't get here until next week so I'll have to wait...
 
You must log in or register to reply here.
Back
Top