Overclocking XP2600+ (FSB333) on MSI KT3 Ultra2 board

I have bought a XP2600+ (FSB 333) processor and would like to
overclock it on my KT3 Ultra2 board. I am using PC2700 memory. I have
tried to change the multiplier from 12.5 to 14 in the bios but the
system is only recognising it as a 863Mhz processor (multiplier 5x)
for some reason. I don't think that I can up the FSB much as the
system seems to get unstable when I do so. What to do ?

(bas alberink) wrote in message . com...
I have bought a XP2600+ (FSB 333) processor and would like to
overclock it on my KT3 Ultra2 board. I am using PC2700 memory. I have
tried to change the multiplier from 12.5 to 14 in the bios but the
system is only recognising it as a 863Mhz processor (multiplier 5x)
for some reason. I don't think that I can up the FSB much as the
system seems to get unstable when I do so. What to do ?

Your mobo probably cannot communicate with the 5th 8X Bit Value bit in
AMD's Multiplier code. So there is no way for your mobo/bios to change
its default LO, (at default 12.5X166MHz setting), to a HI required for
all settings of 13X and up. Instead it is probably setting your
attempt at 14X to 5X, which is a legacy Duron/Tbird issue.
You will most probably have to open the 5th rightmost L3 bridge or use
the fine wire u-loop workaround in sockets AJ27 and AH26 or AK26 to
reset that bit HI. Then set 8X Less than desired in bios, example, to
get 16X set 8X in bios. But beware as NOT ALL settings will be 8X
different, check the Table of settings in link below...14.5X, 15.5X,
17.5X, 18X, and 18.5X are all "additionally remapped".

Read about these issues at...
a href="http://www.beachlink.com/candjac/index.htm"
http://www.beachlink.com/candjac/index.htm/a
Link to Workarounds article. Multiplier Code article also worth a
read. Then you'll understand the issue and verify if it is indeed your
issue.
John C.

(bas alberink) wrote in message . com...
I have bought a XP2600+ (FSB 333) processor and would like to
overclock it on my KT3 Ultra2 board. I am using PC2700 memory. I have
tried to change the multiplier from 12.5 to 14 in the bios but the
system is only recognising it as a 863Mhz processor (multiplier 5x)
for some reason. I don't think that I can up the FSB much as the
system seems to get unstable when I do so. What to do ?

Addenda:-
Note that when you reset the 5th bit HI, the default 12.5X setting
will change to 4.5X which remaps to 20X, (this is covered in the
Workarounds article at the XP2000+ case, also at 12.5X). So its very
probable that 20X166MHz will not boot.
You will have to be able to get into the bios as soon as possible
before the system hangs to change the setting to a more reasonable
8X/16X...or 5X/13X just for a safe first try. Or...you can preset the
System clock to 100MHz where 20X100 should be bootable in Auto detect
Multiplier mode, prove out your mod and the ability to get into the
bios before hang....then reset things in bios to "test" various
settings at 13X and up at 166MHz, (btw, 333MHZ is the "double" data
rate/DDR not the system clock/FSB frequency).
John C.