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Questions about cpu frequency

In a nutshell, ubuntu 13.10 doesn't scale up any of my cpu frequencies when one of the threads is in 100% use. Is this normal?

My CPU: i5 4200u, 4 threads, @1.6GHz up to 2.6GHz.
My OS : Ubuntu 13.10 with kernel 3.11.0-17

Other infomation:

Code:

$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies 

1601000 1600000 1500000 1400000 1300000 1200000 1100000 1000000 900000 800000 



$ cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

ondemand



$ cat /sys/devices/system/cpu/cpufreq/ondemand/up_threshold 

95

Problem:
When the cpu is idle, /proc/cpuinfo says all 4 threads are at 800MHz, which is very cool. But when a process is using one thread 100%, all the cpu frequencies are still 800MHz. The OS doesn't scale up any of the cpu frequencies. Is this normal?

I think when one of the threads is 100% in use, this single thread should be scaled up. What should I do if I want this?

Thank you. Sorry for my English.

I don't know if this is exactly the issue I was having. I have a i7-2600k. I could see the normal frequency range, but not the turbo frequencies. Under load, I was using the turbo speeds (set at 4500MHz), but was only shown 3400MHz. I had to use a tool called i7z to show the turbo frequencies. When I upgraded to kernel 3.12, I no longer need i7z to see the turbo frequencies.

Quote:

Originally Posted by replica9000 (Post 5125069)

Thank you, relica9000. I do have the same problem that turbo frequencies are not shown when using kernel 3.11. Today I updated to kernel 3.12 and the turbo frequencies are shown.

But the lowest frequencies, which are correct in:

Code:

$ cat /sys/devices/system/cpu/cpu?/cpufreq/scaling_min_freq 

800000

800000

800000

800000

$

seem not to be used when the system is idle:

Code:

$ grep MHz /proc/cpuinfo 

cpu MHz                : 1688.074

cpu MHz                : 1600.117

cpu MHz                : 1600.027

cpu MHz                : 1604.160

Frequencies in /proc/cpuinfo are always higher than 1.6GHz. (The governors are "powersave" mode.)

What are the real frequencies the cpu is running at? Is the file /proc/cpuinfo giving incorrect infomation?