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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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 ...
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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 ...
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154 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 ...
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CPU usage of KVM

I have a linux host with 4 KVM linux guests. All the guest are pretty much idle, having a load of <0.1 inside the guest. Now, if I do a top on the host, each KVM process is using something about ...
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How can I set the processor affinity of a process on Linux?

The question is all in the title: How can I set the processor affinity of a process on Linux?
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264 views

Was my CPU kinda broken?

Today I've received some message from mcelog utility, Processor 3 heated above trip temperature. Throttling enabled. Please check your system cooling. Performance will be impacted It happens when I ...
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152 views

Exynos 5 DVFS or turning off cores in Ubuntu - Scaling frequency for one of the cores only (dual core) (cpufreq)

I was wondering if there is possible to scale only one of the cpu cores in the A15 in Exynos 5 ? I have tried using e.g cpufreq-set -c 1 -f 500MHz, but both cores are set to the same frequency. When ...
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2answers
109 views

Ubuntu 10.04 on 64bit

I need to download the 64bit version of Ubuntu 10.04, I found this link http://releases.ubuntu.com/lucid/ and select this option: PC (Intel x86) desktop CD But it is x86? And the other 64bit ...
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2answers
472 views

How to bzip a file with minimum cpu percentage?

I am using bzip2 to compress a file,the process takes more that 100% cpu.Is there any way to run bzip2 with minimum CPU precentage.
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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 ...
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2answers
303 views

Why do I have four CPUs listed in /proc/cpuinfo?

When I bought my Lenovo Thinkpad 520, it had Windows installed. I promptly cleaned that out and installed Fedora 16. I recently visited the /proc/cpuinfo and, much to my surprise, discovered that it ...
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117 views

FreeBSD 9,1 - upowerd's cpu consumption off the roof and causes OS to restart

I've been experiencing a really annoying problem with a FreeBSD setup on my laptop. The setup is as follows: FreeBSD 9.1 / KDE4 desktop / Broadcom wireless 4313 through NDIS / Intel GPU with the new ...
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1answer
99 views

Does loadavg affect CPU usage?

Does loadavg affect the CPU usage? Say I see a process consuming 60% of CPU time, both when loadavg (last minute) was 5 and 1, would it be the same?
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i686 versus i486 kernel on an Intel Core i3

I had installed Debian 6 Squeeze on my laptop a couple of weeks ago. Coming from Ubuntu, I did this by downloading the hybrid i386 image and booting it off a USB drive. Now on GRUB, I'm presented ...
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1k views

Running a Snow Leopard 10.6.7 Image on an AMD: The CPU has been disabled by the guest operating system

I am quite frustrated so I have turned to this medium in hoping to get an answer. After reading thousands of forums and trying out various methods (I have lost track what I have tried already) I still ...
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1answer
2k views

High CPU usage with CFS?

I asked a previous question to try and isolate the source of an increase in CPU usage when moving an application from RHEL 5 to RHEL 6. The analysis that I did for that seems to indicate that it is ...
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1answer
449 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 ...
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2answers
2k views

How to get information about word, address size, address bus size, data bus size and instruction bus size?

I was wondering how to get information about the following things from the command line in Linux: word (i.e. the size that the CPU can process at one time, which may not be the OS bit-depth), ...
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How cpu works in conky

I' m trying to setup conky and I saw that I can use from cpu0 to cpu4 CPU0 ${cpu cpu0}% ${cpubar cpu0} CPU1 ${cpu cpu1}% ${cpubar cpu1} CPU2 ${cpu cpu2}% ${cpubar cpu2} CPU3 ${cpu cpu3}% ${cpubar ...
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680 views

Kernel not detecting multicore cpu

Kernel Version 3.3.4-5.fc17.x86_64 CPU info: sashan@dhcp-au-122 ~ $ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 42 model name : Intel(R) Core(TM) ...
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2answers
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Top and ps not showing the same cpu result

This is linked to this question. When I run top I get the following result: pid 3038 is using 18% cpu, however when running the result is 5.5%. And this number does not appear to be changing ...
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2answers
245 views

Monitor single process to logfile perodicly

Based on this question, I would like to log the performance of a specific process, with a frequency of say one second, to a csv (comma separated value) log file. Something like: ...
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2answers
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How do I know which processors are physical cores?

I've got an Intel i7 2700k here, and I'd like to know how I can tell which processors are physical and which are virtual (ie: hyperthreading). I'm currently running a Conky script to display my CPU ...
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733 views

Which “Processor family” to choose under “Processor type and features”?

I have recently compiled a minimal kernel for my Intel(R) Pentium(R) Dual CPU T3400 @ 2.16GHz, and chose CONFIG_MCORE2 (Core 2/newer Xeon) under "Processor type and features > Processor family" I ...
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480 views

How can a single thread use 200% CPU usage?

From the screenshot above of htop output you can see that mysql is apparently using 204% of CPU usage (this is a CentOS server with dual quad-core Intel Xeons). However only one core (8) is doing ...
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Isolating cause of higher CPU usage on RHEL 6 vs RHEL 5

I'm currently looking to move our system from RHEL 5 to RHEL 6, but I've run into a snag with unexpectedly high CPU usage on the RHEL 6 machines. It appears that this may be due at least in some part ...
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On Ubuntu Linux, is it normal for mandb to run continuously (apparently in the background)?

I have access to a Ubuntu Linux node at my institution. The nodes are shared among the group, but typically I am the only person who uses this particular node. I am running a calculation in parallel ...
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1answer
345 views

System IDLE Time > System Uptime?

I was testing out the linux api while working on something but got stuck on the following output. [Abhii@localhost net]$ cat /proc/uptime 39135.53 149657.73 As per specs the first number should be ...
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840 views

script for logging all the stats for a particular process

I want to monitor CPU usage, disk read/write usage for a particular process, say ./myprocess. To monitor CPU top command seems to be a nice option and for read and write iotop seems to be a handy ...
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2answers
1k views

Find the PID of top CPU/MEM usage, save to a shell variable

Is there any way to get the PID of the top CPU/MEM usage, I need to use that in a script, top command doesn't seem to work for it.
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2answers
475 views

Putting Linux processes on certain CPU cores [duplicate]

Possible Duplicate: How can I set the processor affinity of a process on Linux? Computer CPUs have many cores insde them nowadays. I have always wondered if there is a way to, when I start ...
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4answers
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How to get CPU info on a vmware guest

This is a server that is running on Vmware ESXi: SERVER:/root # cat /etc/SuSE\-release SUSE Linux Enterprise Server 11 (x86_64) VERSION = 11 PATCHLEVEL = 2 ...
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CPU or RAM better in old machine?

I'm planning to use one of two old computers as a low-volume backup server. The machine will be online and files will be backed up over ssh/rsync. I will do a minimal install of Ubuntu or Debian ...
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Invoking CPU Stress

Looking for an app or tool to invoke CPU usage on my virtual Linux and Unix guests. I found the app "stress" from a post on Stackoverflow, but curious what the Unix/Linux crowd would recommend.
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Java problem - nearly looks like a virus?

I have a weird problem since about a week. When I wake up my computer from suspend, a java process starts and consumes about 170 % CPU capacity. I analyzed the java process a bit: it connects to ...
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1answer
679 views

Do I have PCLMUL instruction set support?

Here are the flags from /proc/cpuinfo: fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx rdtscp lm constant_tsc ...
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1answer
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CPU and core usage stats

I'm running some programs on a server and I would like to know how much % cpu I'm taking up and how many cores are being utilised by my process. To clarify, the server has 16 CPUs, all quad-core. I ...
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680 views

Is it possible to limit how much CPU power a process can take?

I'm wondering, is there way to tell a process how much processor power it can take? The problem is I'm converting video with Arista (video converter) and I'm annoyed by the fan running like crazy, ...
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VirtualBox guest: 16 CPUs detected but only 1 online

I am running VirtualBox (using the Qiime image http://qiime.org/install/virtual_box.html) The physical hardware is a 32 core machine. The virtual machine in VirtualBox has been given 16 cores. When ...
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1answer
230 views

Compare usage of memory by window managers

I'd like to test a few window managers to see which of them takes less memory and CPU in certain time period (so is better choice for older computers). I'd like to make the tests myself (not to read a ...
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2answers
572 views

How can we use the command 'top‘ to monitor the total CPU usage and each processor usage simultaneously?

You know that we can use the command top to monitor the real-time CPU usage and toggle the result display to the per-processor view by pressing key 1. The disadvantage of it is you can only monitor ...
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2answers
420 views

Will enabling Hyper-Threading create two virtual half-speed processors?

If I enable Hyper-Threading for my netbook which has an Intel Atom (1.6 GHz) will the kernel see two virtual 800 MHz processors?
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958 views

lshw and lscpu disagree on caches - which is right?

I am trying to find out specifics about caches (in particular which caches are shared between cores and which are not) and have stumpled onto a inconsistency. sudo lshw says *-cache:0 ...
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1answer
233 views

Make effective the changes in CPU governor plugin

I'm using Debian Testing + Xfce. I added to my panel the plugin the handle the CPU governor. My problem is that the setting that I do on the plugin interface are not made effective. Maybe because I'm ...
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1answer
1k views

How to increase Xen guest CPU utilization?

My Xen dom0 is a Gentoo x64 pvops. I boot my guest Gentoo, in PV mode, system with the same kernel my dom0 uses. When I emerge in the guest system, building a CPP package, I am experiencing low CPU ...
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454 views

Overheating results in system shutdown

I have been having an overheating issue which makes my laptop shutdown immediately. Is there anyway to monitor the temperature from the sensor and scale down the CPU frequency to avoid that problem? ...
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992 views

How to find if hyperthreading is enabled on FreeBSD

Is it possible to find out if hyperthreading is enabled within the BSD kernel of a given machine without watching the boot up sequence?
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717 views

Hyperthread and processors Clock, Size, and Capacity

When I enable hyperthreading, CPU size and capacity decrease to about half the non-hyperthreaded value. Since most of my processes use only two cores, should I disable hyperthreading? lshw -C ...
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How can I receive top-like CPU statistics from the shell?

I'm trying to get an accurate read of my used CPU (in percent) from top. This is the command I'm running for testing: top -n1 | awk '/Cpu\(s\):/ {print $2}' This returns: 10.7%us, Which is the ...
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411 views

CPU governor settings

What are CPU governor settings? How can I get their values, if they're set? I have 24 vCPUs on my machine.