Thinkpads Forum

i have a 600x with a 500mhz p3 will all the 600x motherboards suport a 650 p3 with speedstep or do you have to get a diff motherboard im going to have to buy a motherboard anyway becuz i think mine is bad

[IMPORTANT NOTE (added on 24 Dec 2005): The list below of which 600X models support SpeedStep is inaccurate. Some users of 2645-4EU models as well as others have been able to get SpeedStep working. I do not know any longer how to figure out which 600X models support SpeedStep without actually installing a SpeedStep CPU and trying it out.]

Generally, only 600x models that shipped with the PIII 650MHz CPU support SpeedStep.

I'm pretty sure that the following 600X models shipped with 500MHz or less, and do not have SpeedStep enabled motherboards:
2645-3Ex
2645-4Ex
2645-5Ex
2645-7Ex
2645-8Ex
2645-9Ex

The following 600x model was shipped with a 500MHz CPU, but I do not recall if it was ever determined whether or not this model had a SpeedStep enabled motherboard, though I am certain that it didn't ship with a SpeedStep CPU:
2645-8Px

Part of the reason for thinking that this model might have motherboard support for SpeedStep is that IBM groups it together with two SpeedStep-enabled machines in IBM Document MIGR-4FMNJC:
Overview - ThinkPad 600X (2645-5Fx, 2645-8Px, 2645-9Fx only)

Phil.

well then can i put the 650 or a 800 on the any of the 600x motherboards and get it to run a full speed