Hi. On 2023/06/28 14:24, Michael van Elst wrote: > k...@munnari.oz.au (Robert Elz) writes: > >> cpu0: "12th Gen Intel(R) Core(TM) i9-12900KS" > > The chip apparently reports a Tjmax of 100 C (as for the non-selected chip) > but actually has a real Tjmax of 115 C.
https://ark.intel.com/content/www/us/en/ark/products/225916/intel-core-i912900ks-processor-30m-cache-up-to-5-50-ghz.html ark.intel.com often shows incorrect values. Looking at this page now, it says Tjmax is 90 degrees. Robert, could you show me the output of: dmesg -t | grep Tjmax It seems that the MSR_TEMPERATURE_TARGET's value is not fixed on newer chips. Please test the following diff: https://www.netbsd.org/~msaitoh/coretemp-20230628-0.dif Thanks in advance. > There are two caveats: > > Our driver ignores Tjmax of > 110 C (and uses 100 C as default). If the > chip would report the real value, we would ignore it. > > Intel recommends that the BIOS fakes the value and configures the MSR ten > degrees lower (so you see Tjmax of 90 C). > > > The temperature sensor reading is relative to Tjmax. > > /* > * The temperature is computed by > * subtracting the reading by Tj(max). > */ > edata->value_cur = sc->sc_tjmax; > edata->value_cur -= __SHIFTOUT(msr, MSR_THERM_STATUS_READOUT); > > > So it could be 15C lower than reality (if the default of 100 instead > of 115 is used) or even 25C lower if (if the Intel recommenendation > is followed). > -- ----------------------------------------------- SAITOH Masanobu (msai...@execsw.org msai...@netbsd.org)
