Hello,
I'm having continuous trouble with CPU throttling on my laptop. During
normal usage, i.e. web browsing, compiling software etc, for some reason
the CPU throttling activates and the laptop slows down a lot.
(Note: CPU throttling is not the same as frequency scaling, this problem
has nothing to do with the cpu reducing its MHz because it is idle.)
For example, after a reboot and logging into KDE, I have this situation:
laptop:~ # cat /proc/i8k
1.0 A06 ? 52 0 0 0 0 -1 0
(/proc/i8k is the Dell SMM driver, the 52 means the system is at 52
degrees celcius. The two zero's next to is means the fans are switched
off. )
laptop:~ # cat /proc/acpi/processor/CPU0/throttling
state count: 8
active state: T4
states:
T0: 00%
T1: 12%
T2: 25%
T3: 37%
*T4: 50%
T5: 62%
T6: 75%
T7: 87%
laptop:~ #
Powertop report:
Cn Avg residency (5s) P-states (frequencies)
C0 (cpu running) ( 1,5%)
C1 0,0ms ( 0,0%) 1,80 Ghz 0,0%
C2 16,5ms (98,5%) 1200 Mhz 100,0%
Wakeups-from-idle per second : 104,0
Power usage (ACPI estimate): 20,2W (2,0 hours)
(Yes, the number of wakeups is a bit high, I haven't applied all patches
yet, but the problem occurs when the system is not idle.)
Now, any attempt to go back to 0% throttling fails:
laptop:~ # echo 0 > /proc/acpi/processor/CPU0/throttling
laptop:~ # cat /proc/acpi/processor/CPU0/throttling
state count: 8
active state: T4
states:
T0: 00%
T1: 12%
T2: 25%
T3: 37%
*T4: 50%
T5: 62%
T6: 75%
T7: 87%
laptop:~ #
Does somebody have some tips regarding this? Preventing the throttling or
getting it out of throttling. I.e. it is no problem if the laptop
throttles a bit if it gets hot during work, but when it cools down I want
the speed back.
Does there already exists a way to lock the cpu at 1200MHz if the
temperature is above a certain value? If not I could perhaps write a
program doing this using the userspace governor.
Greetings,
Daniël Mantione_______________________________________________
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