Thinkpads Forum

Is there any way to slow down or throttle back the CPU speed of a Mobile PIII with Speed Step in DOS or DOS Mode?

I just upgraded the CPU in my T20 from 650 to 850MHz. I also upgraded the fan to a later model. It's working fine with Win98SE and XP but the fan runs continually in DOS or MS DOS Mode.

I used a little program called MobileMeter to check the temperature in WinXP. The idle temp is 46°C at 20°C (68°F) ambient. The fan doesn't kick in until the temp gets to 73°C. It took a SpyBot system scan to get the CPU temperature that high.

The fan puts out a lot of heat in DOS which indicates the CPU is running full speed even at idle. I never noticed this with the original PIII 650 CPU.

I do regular backups with Ghost running in DOS so I would like to find a way to slow down the CPU.

I was looking for a software solution like there used to be for the faster AMD CPUs that slowed them down so that they would run cooler in DOS.

I went into the BIOS Power section and changed the AC Power setting from MAXIMUM to AUTO SLOW. Now when I want to run something in DOS like a Ghot backup, the CPU isn't running full blast.

One minor glictch, this is a dual boot Win98SE and XP system. XP automatically adjusts to the settings in Control Panel/Power Options but 98 runs at the slower BIOS setting.

If I change the setting in 98 it changes the BIOS setting. No biggie, I can change the backup settings before running in DOS.

What you want is a small TSR application called DOSIDLE. You should be able to find it with Google. Load it via your Autoexec.bat file and that should help. This is for booting directly to DOS. There may not be much to do about a DOS window in Windows 98. Windows 98 itself uses a lot of CPU if you leave it at a login screen without logging it. It is a Windows 98 problem.

I can emulate all this with Virtual Machines, so I am aware that DOS chews up CPU without DOSIDLE and that is what raises the temperature and turns on the fan.
... JD Hurst

jdhurst wrote:What you want is a small TSR application called DOSIDLE. ... JD Hurst

YESSS! This is what I was looking for. DosIdle, also CpuIdle, Waterfall and Rain for Win98.

A long time ago (1998-2002) I built a bunch of AMD K6-2, K6-3 and Athlon desktop systems. I never paid to much attention to these CPU cooling programs because I used big heatsinks and fans and didn't do any gaming so I never had a heat problem.