The CPU (Central Processing Unit), is the chip in the computer that actually performs the operations and calculations that are done as a program runs. It is essentially what executes a program.

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How to find which machines are idle on a cluster of many nodes

I run measurements on a cluster consisting of 32 nodes/machines. I do not require all nodes, only 4, for example. The problem is most of the time, the nodes are busy with other people running their ...
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Is the sum of all PIDs “utime” the total system utime?

In order to measure a user's total CPU time, I'm using the "utime" field out of /proc/[pid]/stat: utime %lu Amount of time that this process has been scheduled in user mode, measured in ...
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Is there a log of past threads that are now closed?

Sometimes, I have a rogue Java process which takes up 100% of my CPU and makes it jump about 30C in temperature (usually resulting in a crash if not killed). Problem is, I can never really identify ...
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409 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 ...
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CPU locked at lowest frequency, cpufreqd says it won't manage it?

I have a Dell Latitude D600 running CrunchBang Statler (Debian Squeeze-based) with a 1.4GHz Pentium M. I noticed in Conky that my CPU freq is stuck at 600MHz, even when doing CPU-intensive things like ...
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Slow down the CPU

I tried to slow down my CPU with powernowd and cpufreq-selector. I hoped that with lower frequency it will be less hot and I won't hear my fan every time I will run internet radio. I used the ...
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Why does top report the incorrect CPU usage?

I have a machine with Intel(R) Xeon(R) CPU E5520 visible as 16 logical cores (8 with HT). If I run something to eat CPU time (single threaded) top correctly reports 100% CPU usage for the process but ...
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How to find out how many cores (including emulated via HT and such) are avaliable to user?

I wonder how to get how many cores (including emulated via HT and such) are avaliable to user via bash shell-script command?
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How can I keep track of what's using the most CPU?

I use nagios to monitor my server. Once in a while I'll get a report that the CPU load is warning / critical, etc. Usually this happens at some odd hour or when I don't have the tools to immediately ...
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How to identify if there is some power saving setting that powered down a processor in Linux

I have a linux server that apparently has two Intel Xeon X5670. /proc/cpuinfo shows 12 CPUs but dmidecode shows only one CPU and the other one is in the Unpopulated status like it is showing that ...
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/proc/cpuinfo “cache” category: L1, L2 or total?

When I look in /proc/cpuinfo, one of the lines tells me I have 6144 KB of cache. Is this L1 cache, L2 cache, or the sum of both of them? In any case, how do I find out how much L1 and L2 cache my ...
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What tool(s) should I use to test my hardware for errors?

Are there any Linux tools (command line, or Live CD) that will test hardware components for errors (hard drive, RAM, CPU, graphics card, buses) and show me some detailed output with wrong parts etc.?
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Only one CPU core is active on Fedora 16

I've upgraded from F15 to F16 and noticed that I have a problems with hardware detection. Upon loading I can see message like ... CPU#1 not responding ... on the screen. It disappears and I can ...
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How can I know which IRQ is responsible of high CPU usage

I've moved a server from one mainboard to another due a disk controller failure. Since then I've noticed that constantly a 25% of one of the cores goes always to IRQ however I haven't managed myself ...
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How to maximize the use of computer performance Core i7 [closed]

How to maximize the use of computer performance Core i7 960 / 12GB Ram?. My operating system is Debian 6 (Linux kernel - 3.0.0-1-amd64). I think it does not work very quickly. Looking for some ways to ...
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How to find which Process is causing High CPU usage

Is there any way to find out from terminal which process is causing high CPU Usage ? It would also be useful to order processes in descending order of cpu Usage
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Get CPU utilization stats from C program

I want to read the CPU utilization stats from a C program, I am interested in the percentage of use of CPU, steal time etc. These stats are shown in the 3rd row from the top command. I tried to parse ...
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How can I have 400% CPU occupied on 2 cores

I understand that Σ(%CPU) ≤ logicalcores*(1+ε) (where ε is measure and rounding error). But, how can I have on a 2 core system 2 different processes, each taking 200% of CPU (as measured by htop)? ...
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Xorg increases cpu usage over time

I've had quite a strange phenomenon with Xorg for some time now: After logging in to my laptop (specifics below) the cpu consumption of Xorg increases monotonically, even if the computer is idle and ...
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Program to test CPU load and process priority

I am running some test on Amazon EC2 instances and we want to make the CPU always busy at above 80%. What I have is a program main that needs to run in high priority and I want to launch another ...
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542 views

Finding MFLOPS using Linux

How can I find out the Mflops on my linux computer? I can see the bogomips on my /proc/cpuinfo but I don't see any Mflops on that file: $ cat /proc/cpuinfo | grep -ie mips -ie flops bogomips : ...
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Why Process CPU % Usage larger than Total CPU Time

When I run the TOP command, a process shows 1208% cpu usage and the total CPU usr time is 81.7% with IRIX mode on. When I change to IRIX mode off, the process shows 99% cpu usage and the total user ...
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766 views

Overclocking software for Linux?

Is most overclocking done strictly at the BIOS level, or is there a way to do it from a running operating system? And if so, is there a way to do it from Linux? I'm running Ubuntu presently and am ...
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368 views

Queries about top command

top command shows the process cpu utilization, and it when we sum the cpu utilization of all the processes then it goes greater than 100%. And how can it shows the cpu utilization of each process( ...
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Run process with higher priority

I want to run mplayer with higher priority than any other processes, including the IO-processes. How can I do that?
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Video player that uses multiple CPU/GPU cores in Linux?

I've got a relative with a four-cour AMD Phenom II 3.0 gHz CPU (can't remember exact specs) and ATI 5750 1GB graphics card, running Ubuntu 10.04. Right now I am aware of VLC and Mplayer for playing ...
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How can I chase a program who is rising up my laptop's temperature?

After 40 days of non-upgrading I came back from a trip and I decided to dist-upgrade my Debian Sid box. Everything went fine but after rebooting I noticed that the temperature was 15°C over its ...