T61 reduced CPU speed after removing battery (AC only)

[saviowong]

Dear All,

I did a clean install of win XP on my T61. After installed SP2 for XP, the CPU speed is slowed down from 2GHz to 1.18GHz. The problem was solved if I put the battery back to my T61. Is it a bug? how can I run my T61 at full speed without putting the battery in? Any help is much appreciated!!

best..........savio

[Thibault]

That's an interesting problem. At first I thought your CPU was just throttling down to save power (which is normal) but that doesn't sound like its the case.

I did a little research on the forums and that seems to be a common issue:
Look here.
I'm not quite sure what the problm is to be honest. You can check your power settings to make sure they're set to maximum performance on AC.

It slows down to 1.18GHz and never goes up to 2GHz? It's normal for the CPU to slow down when it's not being used to save power (dynamic switching).

[pae77]

I believe that Thinkpads are designed to throttle down the CPU when they are run on AC without the battery installed. Consequently, I never run mine on AC without the battery installed.