>I've installed SXCE b75 yesterday on my Thinkpad z60t (I think it's >truly awesome, all worked out of the box). I run fkrit to install >acpidrv (+ other packages) and the CPU frequency scaling is enabled >(pentium m dothan inside). I didn't thing that was so easy ...
>Then I noticed that my laptop was "silent", the fan keeps rotating at >(very) low speed. That's not a problem for general tasks that don't >require intensive calculations, but if I run some floating point >intensive code the cpu temperature climbs quickly up to 80?? celsius. There are two different types of thermal zones in ACPI: active and passive. Passive thermal zones allow you to report temperatures and don't require any action from the OS . Active thermal zones do require action from the OS. Solaris b75 supports active thermal zones because somesystems will die without such supports (overheat or go up in smoke). Generally, though, active thermal zones are considered a bad idea as the system can die when software malfunctions. Worse, some systems require that the CPU is throttled down when it gets too hot. (E.g., the Ferrari 3400 has this issue: it cannot run its CPU flatout all the time, it will die; worse, we've had instances where they were shutdown in Solaris but rebooted into Windows and then burned up (after being closed and stuffed in a carrying bag) I would be surprised if the z60t had an active thermal zone; and I would hope that the Solaris power management driver reevaluates the available powerstates when the BIOS so indicates (my powernow driver does as it is required for the 3400) Now, what is hot? 80C seems hot but might not be; some CPUs have a temperature sensor fitted on the outside of the packages others directly on the die. And in some cases, it is more efficient to make the CPU run hot so less cooling is required than CPUs which need to run cooler. The Pentium M Dothans run fine upto 100C; some Core 2 Duos can not run hotter than 60C. If you installed the acpidrv from frkit, the "batstat" command will list all thermal zones with critical temperatures and active thermal zones. Casper
