still struggling with my P5B Deluxe- what I can't understand is that it HATES 400 fsb upwards .... ! this is with a E6600.

@ 3.25 gig (ie 360x9) - 1.5 Vcore - stable - boots fine - Orthos stable

@ 3.2 gig (ie 401x8) - 1.525 Vcore - set bios -restart - fine -seems to be Orthos stable

BUT press reset and you've only about a 1 in 4 chance of it booting - and quite often you'd have turn on and off at the back to get the "overclocked failred" to trigger ...

409 upwards - and gets even worse - can take say 10 off/ons on the power to get into overclocked failed - and once at 415 I had to do a complete battery out CMOS reset !

any ideas please ?

I've tried VMCH low and high, same with VSB etc ...

I'm a bit concerned to whether its a mobo limitation or a CPU limitation .. ie have I hit a fsb wall on the CPU ? (ie why does it work fine at one frequency at 9x but at 8x but same freq - its a no-no ? - only difference is fsb is higher)

or a mobo limitation - this concerns me a bit more as if I buy another CPU at some point - I may hit the same limitation ?

just confused really -any ideas please ?

I also tried 1:1 RAM, 4:5 RAM, and I've had 2 sets of RAM in the mean-time - one Corsair, and one Crucial Ballistix - same results.

any ideas please ? or just very poor CPU wrt fsb overclocks ?

thanks, Mark.