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6
votes
1answer
373 views

Can I run multiple cores at different clock speeds?

I see the cores on an Intel i5 machine I'm looking at can only be run at the same clockspeed: /sys/devices/system/cpu/cpu1/cpufreq/related_cpus lists all of the CPUs. Setting cpu1's clockspeed changes ...
5
votes
1answer
253 views

Has anyone actually tested laptop battery life under different CPU governors?

In theory, switching from the ondemand governor to conservative should save battery life on laptops. However, I don't think I've ever seen any tests done to verify this or show how significant a ...
5
votes
1answer
306 views

Loading speedstep_centrino kernel module

Because of a noisy fan in my laptop, I need to change CPU frequency and for this task I need to load the appropriate kernel module. The CPU in my laptop Acer TravelMate 4002WLMi is: $ cat ...
4
votes
3answers
2k views

Host CPU does not scale frequency when KVM guest needs it

I have asked this question on serverfault, but it could also have been posted here. I will synchronise the answers if one is found. Observation: I have an HP server with an AMD dual core CPU (Turion ...
4
votes
1answer
199 views

Control cpu freq depending on ac/battery state

How can I make my linux system (ubuntu) automatically choose the performance governor when it works with ac and switch automatically to ondemand when it is on battery (and vice versa)? Is it also ...
4
votes
1answer
2k views

Setting CPU frequency guidelines

I'm changing my CPU frequency because of noisy fan. I used sudo cpufreq-selector -g powersave for this purpose, but I replaced my Linux system Xubuntu with Lubuntu because it utilizes better ...
3
votes
1answer
73 views

How to set the CPU freq. in Linux?

I'm using this ARM9 SAM9G25 embedded system, that when switched on, is only online for a few seconds and because I want to speed up the whole process, I'd like to check the CPU frequency, and set it ...
3
votes
1answer
134 views

How to measure the clock pulse of my computer manually?

My PC has two processors, and I know that each one runs at 1.86 GHz. I have just read about clock cycles and I only have a (very) rough understanding, so I apologize beforehand if my question is so ...
3
votes
1answer
55 views

CPU Frequency changing every second

I just installed conky and recognized that my CPU-Frequency changes every second in steps of 10 to 100MHz and between 1000MHz - 2000MHz. Just wondered if this is normal behavior?
3
votes
1answer
1k views

cpufreq-set -g performance doesn't work on arch linux

acpi-cpufreq was already loaded , where the frequency was all 800MHz now , and I can't make it back to full-speed , which is 2500MHz. I tried cpufreq-set -g performance , then I check /proc/cpuinfo , ...
2
votes
2answers
977 views

How does CPU frequency work in conky?

I'm setting up conky and I would like to add the CPU frequency, but if I put ${freq_g cpu0} Ghz I get 1.2Ghz. Why is that? My CPU is 2.8Ghz.
2
votes
1answer
109 views

How to get ondemand governor on fedora

In Ubuntu 13.10 on my (Dual Core i5 Lenovo G570) laptop, I recently discovered the wonders of indicator-cpufreq, so I can extend my battery life dramatically by setting it to 'ondemand' or 'powersave' ...
2
votes
1answer
614 views

Why do cpuinfo_cur_freq and /proc/cpuinfo report different numbers?

When I do sudo watch -n1 cat /sys/devices/system/cpu/cpu*/cpufreq/cpuinfo_cur_freq I get 1.8 - 2.7 GHz. It never goes above 2.7. And when I do watch -n1 "cat /proc/cpuinfo | grep MHz" I get ...
2
votes
1answer
2k views

CentOS conservative governor, nice error

I changed my CentOS 6 CPU governor from ondemand (the default one) to conservative and got this after restarting the cpufreq service: /etc/rc5.d/S13cpuspeed: line 88: ...
2
votes
1answer
646 views

FreeBSD CPU frequency scaling on AMD Sempron 2100

I have FreeBSD 9.0-RC3 installed on an HP Thin Client that has a Mobile AMD Sempron(tm) Processor 2100+. I am trying to get cpufreq and powerd to manage the frequency of the processor, but I'm not ...
2
votes
1answer
750 views

Scaling issues of i7 3520M with intel_pstate module on Kernel 3.10.0

Few days ago I updated my openSUSE 12.3 system from Kernel 3.9.8-1.gf3348a8-desktop to 3.10.0-1.g3dcd746-desktop and since then, turbo mode of my i7 3520M is enabled by default and it does not ...
2
votes
0answers
140 views

Unable to reduce core frequency freebsd

I'm working on a FreeBSD project where I need to maintain the temperature of the processor below a threshold value. In order to reduce the temperature I'm trying to dynamically change the frequency of ...
2
votes
2answers
2k views

Calculating total CPU system usage in C

I found this answer on StackOverflow for calculating total CPU usage: http://stackoverflow.com/questions/1420426/calculating-cpu-usage-of-a-process-in-linux/4497769#4497769 But how do I calculate ...
2
votes
1answer
296 views

cpufreqd does not control temperature plus shows no output

Since my laptop (an Acer Aspire 5750G running a Gentoo Linux with a not-quite-up-to-date kernel 2.6.39-r3 (a weird wLan hardware makes the update difficult)) tends to run rather hot I am trying to ...
1
vote
2answers
70 views

Linux and CPU usage

What does it mean for a core to run at different loads in different moments? How does a 10% load differ from a 90% load? How is this number calculated, essentially?
1
vote
4answers
74 views

command to find processor speed on zlinux machine

I have the following system : $ uname -a Linux <machine-name-snip> 2.6.18-92.el5 #1 SMP Tue Apr 29 13:16:58 EDT 2008 s390x s390x s390x GNU/Linux $ cat /etc/redhat-release Red Hat Enterprise ...
1
vote
1answer
162 views

CPU fan extremely fast even with 0% CPU [closed]

I just reinstalled my operating system (Crunchbang on Debian testing), and all of a sudden the fan is running as fast as it can even with 0% CPU. The air coming out of it is cold. The only CPU ...
1
vote
1answer
328 views

Ubuntu- How do I change clock speed from terminal? [duplicate]

The title of this question pretty much says it all. What command or program do I need to run in order to change the clock speed to a specific value I want? For example, I'm looking for something like ...
1
vote
1answer
368 views

Process priority and cpu speed

In some devices the cpu speed is dynamic, being faster when there is more load. I was wondering if it is possible to set nice level or priority of a process so that it does not influence an increase ...
1
vote
1answer
113 views

Setting CPU governor to on demand or conservative on Arch Linux

I'm struggling with cpupower on ArchLinux. I want to set governor to ondemand or even to conservative. First if I do $ sudo cpupower frequency-info --governors, I only get performance powersave. So ...
1
vote
1answer
193 views

Where can I find cpu temperature and frequency without any specific command?

I want to make a shell script that runs as a daemon process and every X minutes read the temperature of every cpu core to report it later with GNU plot. And here is my question, Is there any file in ...
1
vote
0answers
86 views

Intel Turbo Boost apparently activated for no reason?

The other day, I reinstalled my operating system (Crunchbang, fork of Debian). For some reason my fan has been running at full speed (and blowing colder-than-room-temperature air) even though I'm ...
1
vote
0answers
877 views

Intel Core i3/i5/i7 Sandy Bridge CPU throttling

Intel Sandy-Bridge family i5 Core CPU, running Linux kernel 3.2 (Debian Squeeze/Wheezy), under heavy computation load, does not react to to cpufreq-set -g powersave (using acpi_cpufreq module). It is ...
0
votes
2answers
419 views

Powersave governor as default Arch

I try to change governor from "ondemand" to "powersave" like wiki says ( https://wiki.archlinux.org/index.php/CPU_Frequency_Scaling#Scaling_governors ), but everyway I want to change it, Arch always ...