Why do some P5-Bs not like 400+ fsb

Buckster

Buckster

Buckster

Soldato
Joined
20 Aug 2006
Posts
9,747
I hear everywhere how the P5-B is unstable at about 340 + - but then becomes stable at 401+ as it changes strap ?

I can't get mine anywhere near stable at 401+ - but its fine at 365fsb ... any ideas ?

so at x9 multiplier I can get up to 3.33 or so - fine

but even at 401x8 - ie 3.2 - and at higher vcore - it just won't play ball

its spectactularly bad too - sometimes bios freezes as soon as you set 401x8 and press save - sometimes the pc will not even post

I even tried manually setting the mobo voltages- to no avail.

is it just motherboard variation ?

I know the RAM can take it, I know the CPU can take it ??

thanks,

cheers, Mark.
 
Ulfhedjinn - does yours managed 401 + fsbs ?

odd that mine and my friends both don't - we have the same RAM though - I'm wondering if some RAM doesn't like operating at that fsb - mine is rated at CAS5 - DDR 800 - so should be OK -but there is a large difference in actual RAM bandwidth vs 266x9 and 401x8 (much higher sisoft score)

Something obviously doesn't like it at all - as I said sometimes bios even crashes, or pc won't even post.

yet if I push it up to say 3.4 gig @ x9 multiplier, it will boot - just will fail Orthos etc - much less spectacular failure though

Mark.
 
eeek ! - thats good

any idea to what could be causing my 401+ fsb problems ?

it hates it so much must be something - but I can't fathom out what

CPU has enough Vcore - and I know it will clock higher at x9

RAM should be OK - have had it stable up to 890 MHz - but perhaps it doesn't like the 1600+fsb

Component on the motherboard itself ?

Mark.
 
thanks very much - as I said its very severe crashing wise anything over 401

interesting that it hangs sometimes as soon as you press F10 to save and exit bios ...

Mark.
 
some extra details

currently on 1.9-1.95V Vdimm

RAM is Corsair 6400 C5 (PROMOS :( ) - doesn't like volts at all

CPU = 6600 - Week 24 - not great overclocker, but will do 3.33 @ 1.5V (bios)

have C1E and EIST disabled
USB Legacy off

all Motherboard Volts at Auto

CPU @ 1.5V @ 3.33 gig is about 56C load (TAT) and 42C idle - so I don't think temps are my probem

is your GEIL the "standard" C4 stuff ? I may be tempted as its very cheap now - my Corsair is very poor - currently running it at 700MHz (1:1) - C4 - which its fine at.
 
You must log in or register to reply here.
Back
Top Bottom