Confused

[gb]

I have replaced motherbord for my T21 2647-47U 800MHz P3 and noticed that, Windows XP system information shows only 647MHz processor, while BIOS shows true 800MHz. I heard something about StepTechnology, but should it reduce the speed of the processor while running on the battery? I am running of AC power.

Can somebody educate? Is something I should do on motherboard or in winXP setting, or it just another "feature" of the Microsoft Windows.

An another question, while I got your attention...
The BIOS version for this board is for T20 thinkpad, while I am replaced it on T21. Is this machine become T20 after the board got replaced or I still should update to latest T21 Bios?

Thanks in advance