-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi all, I already answered this thread while ago. I can just confirm what Jean told. >>>> I confirm this. >>>> I *know* that temperatures reported now are wrong. > > And how do you know? The newly reported temperatures could be correct > and the previous ones were incorrect (that's actually the case.) The > thing is, the temperature is stored as a relative value in the CPU. > Relative to what, depends on the CPU model, can be 85°C or 100°C. Up to > kernel 2.6.24 we had a set of rules to find out, in 2.6.25 we have a > presumably better heuristic. So some people have seen their CPU > temperature climb by 15°C and others drop by 15°C, that's expected. Yes exactly. I decided to move to 0-100C scale, and move the limit too. Of course some users with too low jumped to better scale some like you seems to complain now. >>> i have watercooling, and well :P when i touch the "tube", its normal >>> room temperature, and believe me, i would notice if it was 45.. this is >>> with my cpu at idle - at full load on all 4 cores, temp2 says 35, and >>> ~60 on coretemp, and THIS i would surely be able to notice over room >>> temp :) > > The coretemp driver reports the CPU _core_ temperature. That's not > something you can touch, believe me (unless you are an electron.) > > Also note that the CPU temperature reported by the IT8718F may or may > not match the reality. To make sure, you'd need to know the type of > thermal diode expected by the IT8718F, the type of thermal diode in > your CPU, compute the correction factor if there is one. And you'd need > to know where the thermal diode is exactly. It is most certainly built > into the CPU, but some motherboard makers are doing weird things. > > 22°C seems very low to me, even for water-cooling. Note that > non-linearity of thermal diodes makes measurements inaccurate as they > get away from the expected operating point. I guess that thermal diodes > used in CPUs are calibrated for best results around the expected > temperature when using air-cooling, rather than water-cooling. > >>> any progress on this bug? > > I still need to be convinced that there is a bug here. It is not a bug, a max limit changed too, it is just matter how to scale it. The temperature is non-physical so comparing it to physical temperature does not make any sense. I'm sorry I did not invent this relative temp stuff - Complain @intel. They have some calibration of TjMAX for mobiles, but this bit does not work for desktops/servers. I tried really hard to get at LEAST some documentation so the driver looks like it looks. And not guessed/guessed/guessed/how it looked earlier. > >>>> The reason is that bios did report same temperatures as coretemp in 2.6.24, >>>> moreover some time ago I have run a cpu tool (don't remember its name) on windows It was most likely coretemp - I'm in contact with the guy. We share infos. >>>> temperature of both cores >>>> (I had to run this on windows - intel haven't released >>>> drivers for their QST for temperature monitoring from bios - very sad) >>>> >>>> And the driver did say in kernel log that TJMAX is 85C > > Which driver, which kernel? As I wrote above, the coretemp heuristic > changed in kernel 2.6.25, so the fact that a previous kernel was > reporting a different tjmax value is irrelevant. Unless you have > additional documentation from Intel, I would tend to believe that the > coretemp driver in 2.6.25 is correct. But feel free to report the exact > CPU model you have (with CPUID info) to Rudolf, if he gets enough > reports about a specific CPU model which most people believe gets the > wrong tjmax, he can fix the driver. Well again, I tried hard at Intel and I really could not get any info on some calibration bit. The temperature is non-physical on arbitrary scale. I changed that so for some people it jumped to 100C, for some it remained. >>>> Lets at least make a kernel option to override tjmax? > > That's a possibility for sure, but what we would really need is to > adjust the coretemp driver heuristics to always get it right - if > that's not already the case, that is. I'll let Rudolf decide anyway. Well again, Intel swears there is no way how to get the TjMAX for desktops/servers. It sucks but this is not my fault. Thanks, Rudolf -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFIF5203J9wPJqZRNURAnFSAKC3GpafvkviWggGJPG2o71R4lel0wCgirnW Cr2RidnTZEdKTAj8yEviR0U= =lFMk -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
