# cpu sometimes very slow

## ccube

Hey folks,

i've got a dell studio 1558 notebook with a i7 820qm processor.

sometimes (not always) compiling is very slow and with 100%cpu load it is most of the time in C1 state.

after rebooting the system i can kick the cpu to 100% c0 when burning all cpus with emerge chromium or sth. like that.

what might be wrong here? where to start investigating?

```

Cpu speed from cpuinfo 1728.00Mhz

cpuinfo might be wrong if cpufreq is enabled. To guess correctly try estimating via tsc

Linux's inbuilt cpu_khz code emulated now

True Frequency (without accounting Turbo) 1728 MHz

  CPU Multiplier 13x || Bus clock frequency (BCLK) 132.92 MHz

Socket [0] - [physical cores=4, logical cores=8, max online cores ever=4]

  TURBO ENABLED on 4 Cores, Hyper Threading ON

  Max Frequency without considering Turbo 1860.92 MHz (132.92 x [14])

  Max TURBO Multiplier (if Enabled) with 1/2/3/4 Cores is  23x/21x/15x/15x

  Real Current Frequency 1993.94 MHz [132.92 x 15.00] (Max of below)

        Core [core-id]  :Actual Freq (Mult.)      C0%   Halt(C1)%  C3 %   C6 %  Temp

        Core 1 [0]:       1993.85 (15.00x)      39.6    54.3       0       0    86

        Core 2 [1]:       1993.87 (15.00x)      76.7    11.5       0       0    90

        Core 3 [2]:       1993.94 (15.00x)      14.9    82.8       0       0    87

        Core 4 [3]:       1993.93 (15.00x)      15.3    82.4       0       0    87

C0 = Processor running without halting

C1 = Processor running with halts (States >C0 are power saver)

C3 = Cores running with PLL turned off and core cache turned off

C6 = Everything in C3 + core state saved to last level cache

  Above values in table are in percentage over the last 1 sec

[core-id] refers to core-id number in /proc/cpuinfo

'Garbage Values' message printed when garbage values are read

  Ctrl+C to exit

```

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## audiodef

Your CPU has four cores. Do you have MAKEOPTS="-j4" in /etc/make.conf or /etc/portage/make.conf?

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## LiamOS

As mentioned above, MAKEOPTS is something you should have set at -j4, or possibly -j5. Also, check if you have PORTAGE_NICENESS set, as this might have some effects.

Did you configure your kernell yourself? If you have access to a precompiled kernel, you could check if you get the same problems under that. If so, you've ruled out one thing.

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## ccube

My CPU has 4 cores hyper threaded, so i set MAKEOPTS to at least 8.

the log i posted was made, while al 8 logic cores were at 100% load.

my kernel has, of course, a custom configuration.

i regognized that compiling the kernel will result in 100% C0, but compiling chromium behaves like in my first post.

 maybe there is some cpu throttling?

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## audiodef

See what happens if you set MAKEOPTS="-j4". I'm not sure you're supposed to set this for more than the ACTUAL number of cores. Also, I've been told that setting MAKEOPTS to cores+1 provides no real benefit over setting it to to the number of cores exactly.

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