Thanks again for the prompt response. One more question regarding coretemp: any idea how I can probe the sensor in my own source code? I'm hoping to be able to probe a few times a second, while the lm-sensors usage guide says max. probing frequency should be at most 0.3-0.5 Hz. I'm trying to measure thermal response and hence transients. Temperature rises rather too rapidly for this once every 2-3 seconds restriction; there's no intermediate reading between idle temperature (~28C) and loaded (~55C). Even when I overclock to deliberately induce more dissipation, I don't get an intermediate reading between the same base temperature and 70C! Please let me know if the 2-3s resolution is a limitation of the sensors API or the kernel module itself. Any tips on how I might be able to measure with greater frequency (apart from hooking up an external probe and thermometer)? thanks! On Sun, Oct 24, 2010 at 5:42 PM, Luca Tettamanti <kronos.it@xxxxxxxxx> wrote: > On Sun, Oct 24, 2010 at 11:27 PM, Arun Raghavan <arraghav@xxxxxxxxx> wrote: >> Hi, >> >> Thanks for the quick response and the links. I'm not sure I understand >> exactly how to proceed or how to interpret your point about coretemp >> being relative to Tjmax. I see the coretemp value increasing with >> activity, implying the reading is greater the hotter it gets. If it >> were a delta from Tjmax, I would expect it to decrease? > > Tjmax is the upper limit at which the CPU forces the throttling > (AFAIK). The exact value varies between CPUs, in you case it should be > 101°C; the DTS reports a negative value (or rather a positive margin) > relative to TjMax, the driver converts it to an absolute temperature. > Tabs = TjMax - Tdts > >> I also have thermometers probing across the heat sink and they seem to >> match the coretemp readings at idle (of course, when the CPU heats up, >> the package temperature is hotter than the heatsink probe detects). >> Should I just trust the coretemp readings to a reasonable >> approximation? > > I should be :) For some desktop CPU the exact value for TjMax is not > known and is assumed to be 100°C; in this case the driver emits a > warning in the log. > > Luca > _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
