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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So what are logical cpu cores (as opposed to physical cpu cores)?

I was googling about how I could find the number of CPUs in a machine and I found some posts but I am confused as some mentioned that you get the logical cores vs physical cores etc. So what is the ...
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1answer
460 views

How to increase the system CPU load/utilization in Solaris 10 to test nagios?

I want to increase the system CPU load in Solaris 10 in order to test this scenario in Nagios. I'm running following command to get the CPU utitlization in Solaris: bash-3.00# sar -s 10 60 SunOS ...
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2answers
751 views

Does linux kill heavy and long running background processes after they reach some threshold?

If I start a really heavy (memory/cpu intensive) running really long running process will the OS terminate it after a period of time arbitrarily? I.e. are there any limits beyond which the OS would ...
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How can I start a process using cpulimit?

I am trying to use cpulimit for testing an app I'm developing under low resource conditions, and I need the process to start under the influence of cpulimit. It is not sufficient to start the program ...
3
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1answer
236 views

How to assign tasks to GPU

I have found a benchmark from computerbase.de (http://www.computerbase.de/artikel/grafikkarten/2013/intel-haswell-grafik-fuer-desktop-pcs-im-test/3/ in german) where in one case a task (here video ...
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1answer
438 views

xorg performance in openoffice

I've just been monitoring my cpu usage in openoffice calc when cells have been copied vs when they haven't and seen a dramatic increase in cpu usage for the Xorg process. The additional rendering ...
0
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3answers
694 views

High CPU utilization with zip command

When I am using the zip utility in Linux to compress files, CPU utilization is going to 100%. Can anybody help me why CPU utilization is so high? I'm using the command: zip file_name *.xml
2
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0answers
254 views

eldoc makes emacs use 100% cpu

When I use eldoc, I add this to .emacs: (add-hook 'emacs-lisp-mode-hook 'turn-on-eldoc-mode) (add-hook 'lisp-interaction-mode-hook 'turn-on-eldoc-mode) (add-hook 'ielm-mode-hook ...
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3answers
12k views

How to check that AES-NI is supported by my CPU?

Howcan I check if my CPU supports the AES-NI instruction set under Linux/UNIX.
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100 views

Prevent Java to escalate CPU usage on Slackware64?

I use Slackware64-current on my work laptop and though I love running Slackware, sometimes it hangs on me near to the point of starting considering falling back to Windows. I develop on Java and use ...
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3answers
1k views

Determining the particular processor on which a process is running

I have access to an 8-core node of a Linux cluster. When logged in to the node, I can see a list of processors using this command: more /proc/cpuinfo In my 8-core node, the processors are numbered ...
4
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1answer
599 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 ...
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1answer
3k 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
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1answer
202 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 ...
5
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2answers
4k views

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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3answers
2k views

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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3answers
452 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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0answers
219 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
127 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
827 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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0answers
216 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 ...
5
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2answers
330 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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142 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
127 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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1answer
3k views

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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1answer
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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
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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
649 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
3k 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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2answers
2k views

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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2answers
1k 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
321 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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1answer
1k 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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0answers
582 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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4k views

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 ...
4
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3answers
3k views

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 ...
2
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1answer
491 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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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
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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.
2
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2answers
666 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 ...
2
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4answers
12k views

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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3answers
211 views

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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2answers
1k views

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 ...
3
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1answer
846 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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826 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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2answers
3k views

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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2answers
907 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
520 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?