duron 600 / msi k7t pro 2a

[Jeb]

I try to boost this config, I need advice!!!
L1 shorted whit pencil

I change de clock ratio in the bios and when i reebot... cpu: 500 mhz
Why? and when i turn the computer off then the reboot.. cpu : 600 mhz

Somebody can help me??
What is the best setting, voltage, clock, fsb

Thanks for the help,

and sorry for my poor english!!