Inspiron 2500 CPU not reading correctly

[gloptnitch]

I am upgrading a Dell Inspiron 2500. I took out the PIII 800 and put in a PIII 1GHz. Both CPU's have the same BUS, CACHE and pinsets. When it goes through POST it states there is a PIII 1GHz, but after windows loads and I bring up System it only shows a 700 MHz CPU. I have already flashed to the most recent BIOS that Dell had to offer. The laptop is pluged into AC so it is not in "Power Saving" mode which slows the CPU down. Even if it was, System should show the full processing power, not what it is running at. If you want the specs, the tag number is 9J91T01. the only upgrades were the CPU to 1GHz and the RAM to 512. It is also running XP Home. Any ideas why it only says 700MHz instead of 1GHz in System?

 

[HSC]

I am not certain with Dell but with IBM Thinkpads when this difference between the CPU speed the BIOS finds and the CPU speed reduced while running Windows is down to Intel Speedstep getting it wrong

Try booting to a desktop with AC power then unplug to run on battery for a few moments then plug the AC power again this action can sometimes jolt speedstep into action

also check in BIOS setup for settings related to CPU power although in my experience the descriptions on what these features can be missleading to say the least

Cheers HSC