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Questions tagged [cpu-frequency]

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31
votes
1answer
61k views

Setting CPU governor to on demand or conservative

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 ...
21
votes
1answer
24k views

Can't use “userspace” cpufreq governor and set cpu frequency

I'm trying to change the cpu frequency on my laptop (running Linux), and not having any success. Here are some details: # uname -a Linux yoga 3.12.21-gentoo-r1 #4 SMP Thu Jul 10 17:32:31 HKT 2014 ...
11
votes
1answer
19k views

How to set up Linux for full AMD APU power management support: Turbo Core, Cool'n'Quiet, Dynamic Power Management?

My objective is to set up a mini server (not HTPC) with low power consumption in idle mode, yet offering nice performance when used. The focus is more on data safety than availability. In other words: ...
11
votes
1answer
23k 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 768 ...
8
votes
3answers
12k 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 ...
7
votes
1answer
5k 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 ...
7
votes
1answer
1k 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
20k 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: /sys/devices/system/cpu/...
5
votes
2answers
4k views

Is it possible to set a *constant* lowest CPU frequency under the modern PSTATE driver?

The new pstate Intel driver pisses me off for good, because they have removed the good old powersave governor that allowed me to set the lowest available CPU frequency and run my numerical simulations ...
5
votes
1answer
592 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
5k 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 ...
5
votes
0answers
428 views

Loading speedstep_centrino kernel module [closed]

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 /proc/...
4
votes
2answers
3k views

What are the implications of setting the CPU governor to “performance”?

I recently read that I can eke more performance out of my CPU by setting the governor to "performance" instead of "powersave". According to the Arch wiki, this will "run the CPU at the maximum ...
4
votes
1answer
505 views

What are the frequencies displayed in /proc/cpuinfo?

I have a quad core cpu (core i7 7700) with hyperthreading. cat /proc/cpuinfo | grep MHz returns 8 different frequencies, some of which are not repeated (for example I can get a single value of 3914....
4
votes
1answer
794 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?
4
votes
1answer
1k 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
815 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 ...
4
votes
1answer
2k views

Set critical CPU temperature for thermal throttling

According to sensors, the critical temperature for my CPU cores is at 100°C. When using my laptop it never goes above 95°C (So either my sensor is defect or thermal throttling is set to a lower value ...
4
votes
1answer
639 views

Force Haswell CPU to fixed frequency

For stability of benchmarks I wish to run the E5-2680 v3 2.5 GHz CPUs in my Dell R430 test servers running Fedora 23 at their nominal frequency - no more, no less. I've disabled the intel_pstate ...
4
votes
1answer
13k views

“rcu_preempt detected stalls on CPUs / tasks” message appears to continue

My board continues to display the message below. The terminal does not have any input. What is it with the following message, which I know? (T, g, c, q ...) What is the cause of this phenomenon? ...
4
votes
1answer
496 views

Which is better, High CPU % with Low Frequency or the opposite? [closed]

January 15, 2018 update I created a 90 second Conky .gif showing "normal" behavior during start up: A few seconds after boot I start Conky. A few seconds later I start Peek which begins recording ....
3
votes
2answers
7k views

Kondemand process consumes most of my CPU

Following is the output from top: PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND 3551 mysql 20 0 10.0g 84m 4052 S 9.4 0.1 544:39.87 mysqld 2311 root 20 0 0 ...
3
votes
1answer
5k 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' ...
3
votes
1answer
581 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 want to measure the clock pulse of my PC processor/s manually, and my idea is just to compute the quotient between the number ...
3
votes
1answer
4k views

how to turbo boost my cpu on Ubuntu?

My PC has one Intel Haswell i5 4690, which is supposed to be boosted up to 3.9GHz from the regular frequency 3.5GHz. I do not know if it is possible to use some softwares to turbo boost this cpu on ...
3
votes
1answer
46 views

How can my cpu frequency be above maximum MHz value in lscpu?

How can it be, that my current cpu frequency (CPU MHz) for my Intel Core2 Duo T9400M is above max MHz while being on high load? ➜ lscpu [...] Model name: Intel(R) Core(TM)2 Duo CPU ...
3
votes
1answer
526 views

CPU temperatures in linux: throttling or wrong reading?

Using a Lenovo Legion Y520 with i7-7700HQ (base clock 2.8Ghz) and GTX 1050. I'm getting CPU overheating warnings in linux and it's affecting my performance in games (found in Payday 2 and CS:GO). I'...
3
votes
1answer
2k views

How do I add CPU frequency governors to the Linux kernel?

CPU frequency scaling in Linux is by default performed via a governor, which as far as I know is included in the kernel. So far, on PC/server Linux kernels I've only seen the userspace, powersave, ...
3
votes
2answers
629 views

Set CPU affinity for the specific program?

How can I set CPU affinity for the specific program (say gzip) to always run on specific core or cores (core 1, for example)? I read about taskset, but can it be used before program is actually used ...
3
votes
2answers
3k 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 ...
3
votes
1answer
3k 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 , ...
3
votes
1answer
47 views

How come different hyperthreads have a different clock speed? [closed]

I have an Intel Core i5-2520M CPU in my laptop which has two physical cores and hyperthreads, resulting in four logical cores. When looking at /proc/cpuinfo, I see four different clock speeds: $ grep ...
3
votes
1answer
1k views

Slow down CPU when it heats up

I run Gentoo Linux on my laptop. I have an issue, though, where if I'm building some very large piece of software (as I do fairly frequently, since the purpose of this laptop is development), the CPU ...
3
votes
0answers
108 views

Suspend system instead of shutdown on CPU overheat

I have Linux Mint. The system Linux Mint is installed on, shuts down immediately on overheating. Is there anyway the system doesn't shutdown, but goes to standby state? The machine can always be ...
3
votes
2answers
10k views

CentOS 7 cpupower not setting the CPU's to maximum

On my machine, i have power savings disable on the BIOS. When I run Ubuntu on this machine, the CPU's are running maximum at 2100 MHz. However, when I'm running CentOS 7, even with the scaling ...
3
votes
0answers
305 views

CPU frequency goes back after scaling down by indicator-cpufreq, suspension and waking up

I scale down the CPU frequency by indicator-cpufreq on Ubuntu 12.04. After I suspend Ubuntu and wake it up, the CPU goes back to"on demand" (the default). I wonder if there is a way to keep the CPU ...
3
votes
1answer
1k 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 ...
3
votes
1answer
798 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 ...
2
votes
3answers
342 views

Turn off CPU turbo-boost for a process

When the CPU (Intel i5-8400) is heavily loaded, the fan seems to increase its speed and make noise. I want to eliminate the noise when running CPU-intensive backup process (backup2l program). (It is ...
2
votes
3answers
5k 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
2k views

How to set up a Debian system (focus on 2D or console/server) with an AMD Turbo Core APU for maximum energy and computing efficiency?

I plan to set up an AMD APU system using Debian, but I cannot find hints how to achieve maximum energy efficiency and successful use of Turbo Core. In particular, the Debian Wiki HowTo on CPU ...
2
votes
1answer
2k views

CPU speed and cat /proc/cpuinfo

I use centos 6.4 64. I have old proc - CPU AMD Phenom II X4 810 (HDX810W) 2.6 GHz. However, when I execute the command cat /proc/cpuinfo I get the following: processor : 0 vendor_id : ...
2
votes
4answers
5k 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 ...
2
votes
1answer
4k 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 ...
2
votes
1answer
10k views

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

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 <command name> 1.7, or something similar, to ...
2
votes
1answer
68 views

What does `/usr/lib/pm-utils/sleep.d/94cpufreq` try to do?

On my Ubuntu 16.04, I am trying to understand a system default file /usr/lib/pm-utils/sleep.d/94cpufreq (see the end of this post for its content.) Is "${PM_FUNCTIONS}" a script, given that it is ...
2
votes
2answers
881 views

Why is /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed not modifiable by sudo emacs?

I would like to edit /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed to change its content from 800000 to 1600000. I first try with emacs $ sudo emacs -nw /sys/devices/system/cpu/cpu0/cpufreq/...
2
votes
1answer
3k views

Scale cpu frequency in CLI?

I am using cpufreq to scale my CPU frequency. But I do that by clicking cpufreq icon on the panel of Ubuntu 12.04. If without a mouse, how can I show and scale CPU frequency by running commands in ...
2
votes
2answers
79 views

Linux utility to bench mark clock speed of CPU

I have a Linux PC with a 3.4 GHz CPU. I must check this processor to see if it actually runs at that speed. Is there a benchmark available? I ran sysbench but it only provides time of completion, and ...
2
votes
1answer
2k views

How can I enable Intel's P-State driver?

I am trying to use Intel's P-State driver for my custom-built kernel (based on Linux 4.4.55). I have enabled the driver in the kernel configuration (by setting the X86_INTEL_PSTATE flag to "*"), but ...