T43 Win XP Stuck at low CPU frequency

[mark-ibmtp]

Running XP SP3 (I know, I know)

Within the past couple of days, I noticed that two things about the old T43:

1. It runs even slower than usual

2. The fan runs very little, with temperatures staying low (49-54C)

I put on the Windows Performance Monitor (perfmon), which shows the clock frequency rock-steady at 46% of rated frequency, regardless of CPU utilization.

The one thing I could think of to check was the power manager mode. I verified that it was as usual, and even incremented the performance level one notch to the maximum -- this made no difference.

I have NEVER changed the BIOS settings on this machine, and have made no recent system configuration changes or software installs. I reboot this machine as little as possible (it takes a while to start everything up), and this change seems to have happened since the last reboot (that is, CPU could go to max when I last rebooted, and the slow-down happened without XP restarting). I do often sleep the machine (suspend to RAM).

The machine shows no other symptoms -- apart from the low clock frequency, all is running stably.

Is there anything I can check in registry etc?

Thanks for any suggestions!

[ajkula66]

How is your battery?

[RealBlackStuff]

Maybe your battery is dead?
If run only on AC, those machines have a habit of running slower.

[mark-ibmtp]

The battery is old, but can still power the T43 for almost 60 minutes.

In my history with these machines, I have not seen battery condition affect the performance when on the AC power supply. Sometimes I run T4xs without any battery at all!

However, your comments jogged my brain (which is also old!), and I did recall that I have run this T43 on battery for one session since the last reboot.

Just now, I unplugged the AC PS and immediately re-plugged it. Et voila, the clock frequency jumped to 100% -- and the fan immediately came on

I guess that the Power Manager somehow left the Speedstep mode in power-saving when I returned to AC power a couple of days ago. Power manager knew that the T43 was no longer running on battery, because as soon as I went off-battery (two days ago) the LCD returned to full brightness etc.

Probably there was some glitch in changing the Speedstep mode ... and once it is supposed to change, Power Manager doesn't check or touch it again until something changes with system power.

Thanks for your very quick replies!