CPU stands for Central Processing Unit, and is the main processing chip used in every computer. Brands include Intel, AMD and ARM. CPUs are commonly available in 32- and 64-bit, and come in a variety of frequencies or with multiple cores.

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top command on ubuntu multicore cpu shows cpu usage >100%

I have ubuntu running on a multi-core CPU with 32 cores. When I check the cpu usage using top command, sometime it shows more than 100 %, like 340%, 650% etc. I did some investigation and found that ...
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178 views

Abnormal fan behavior: Sticking and persist on max speed (HP Envy 6-1154er & Ubuntu 14.04)

1. I have HP Envy 6-1154er under Ubuntu 14.04 LTS. I encountered the invalid fan behavior. As cpu load grows and if it makes fan to work on max speed the speed never goes back to "silent mode". When ...
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119 views

Kswapd0 using 100% of CPU

I've got a mini server running (L)ubuntu 14.04.3, kernel 3.4.39. Every once in a while, the process kswapd0 will use 100% of my CPU power, even though I only use about ~20% of my RAM at that time. ...
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1answer
139 views

LibreOffice cpu usage 50% in Ubuntu and Xubuntu 15.10

When I load 400 pages of ODT document in Ubuntu 15.10 and Xubuntu 15.10, cpu usage becomes 31%. It is soffice.bin file. After editing, cpu usage becomes 50% (cpu0: 100%, cpu1: below 10% or vice versa) ...
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1answer
193 views

Issues running ubuntu 15.10 on Acer r3 131t acpi need to be of

I am trying to install ubuntu 15.10 on my acer R3 131T. I have run in to several problems, most of which where easy to fix. However there is this one problem i can't seem to get by. I can not boot the ...
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35 views

Is there certified version of Ubuntu for Dell Vostro 3300 i5?

I recently started using Ubuntu 14.04 LTS. I often get "System Problem" messages, as well as other small issues. (System freezes from time to time, especially when using LibreOffice.) I am not ...
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104 views

Why my desktop Ubuntu system has lag when CPU is not full?

I have a desktop workstation installed with Ubuntu 14.04. It has i7-5820 CPU, 6 cores 12 threads. When I run my 10-threads code which takes up 80-90% CPU usage. (See monitoring statistics below). I ...
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1answer
34 views

What is it called when I have UBUNTU installed in hard-computer?

I want to know what should I call the fact of having Ubuntu installed in the computer itself. I installed it removing windows because I want to install windows on Virtualbox instead. I am not ...
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2k views

how to make cpugovernor intel_pstate stable?

I am trying to set to a specific frequency in cpu governor. However, I am not being able to do so. My processor is 12*Intel(R) Xeon (R) CPU E5-2620 v3 @2.40 GHz With intel_pstate driver it gives ...
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2answers
48 views

CPU Overusage Ubuntu 14.04

I'm very new to Linux and Ubuntu. I did install Ubuntu 14.04 on my Vaio laptop and all was working fine. Yesterday, I did the last update and since then my fan is working all the time. CPU temperature ...
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99 views

Libreoffice 5 in ubuntu 15.10 raising system temperature

I'm using 15.10 upgraded from 15.04 and when I open some documents with new Libreoffice5, the system temperature goes to 60-65ºC (or more!), when normally stands between 45º and 50º. Also, system-...
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1answer
306 views

Why is khubd process using too much of my CPU?

analyzing the process manager I found that the khubd process uses more CPU than other processes all that are running. It uses at least 25% and even uses around 40%. Does anyone know what this process ...
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0answers
51 views

How can I prevent `convert` from causing my system to grind to a halt?

When I run ImageMagick to create an animated GIF from a large number of images, it uses resources such that my i7 system becomes unusable. Within seconds of starting, everything freezes and, ...
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1answer
197 views

Kworker making computer difficult to use

I followed the steps on here Kworker, what is it and why is it hogging so much CPU? to try to figure out why there's a Kworker consuming a lot of CPU power. Normally this wouldn't be an issue because ...
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20 views

stubborn high cpu question w/ hp g6

I've got ubuntu 14.04 installed on my HP G6 laptop Processor: AMD A6-4400M APU with Radeon(tm) HD Graphics × 2 Graphics: AMD Radeon HD 7520G I get very high (40%-100%) cpu usage when watching any ...
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108 views

CPU fan very loud while PC is idle

I am using Ubuntu 14.04.3 LTS. I am rather confused what exactly is wrong. The command 'sensors' shows 33 degrees for one reading, and 69 and 78 degrees for the other two: it8720-isa-0228 Adapter: ...
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1answer
89 views

Antlr can't be found when building Processing

This is my error when building http://www.processing.org/: BUILD FAILED /opt/processing/build/build.xml:309: The following error occurred while executing this line: /opt/processing/build/build.xml:...
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1answer
67 views

unable to open ubuntu in Oracle VM Virtual box [duplicate]

When i start the Ubuntu in Oracle VM Virtual box, it throws following error. This kernel requires an x86-64 CPU,but only detected an i686 CPU. Unable to boot- Please use a kernel, appropriate to ...
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52 views

Unable to install Spotify on Ubuntu 15.04. Where do I find package spotify-client?

I have followed the basic instructions that Spotify.com provides, running the commands. But after running them all I get a message saying "Unable to locate package spotify-client". Now, I read ...
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1answer
62 views

Getting Problems with intel_pstate

Recently, I thought that the graphics drivers are the one causing me very huge lags/hangs on my system. But just earlier, I discovered that the process kidle_inject is causing all this troubles. (Upon ...
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2answers
296 views

Indicator displaying current CPU frequency and usage

Unfortunately, it seems that cpufreq indicator is only showing an icon indicating proportional frequency instead of precise number I would like to see. Is there any indicator showing actual CPU ...
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40 views

Possibility to Limit Processor Utilization by %?

This question refers to the feature in Windows Power Settings that has 2 options: Minimum processor utilization: 0% Maximum processor utilization: 100% Since the default Power Options in Ubuntu ...
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35 views

Unable to install ATLAS even after disabling CPU throttling [duplicate]

I am trying to build a computational tool called SU2 from source on my Ubuntu 14.04.3 and it has many prerequisites, ATLAS being one of them. Being new to Ubuntu, I followed this guide for ...
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118 views

Can Ubuntu tablet run on an A7 CPU?

I was wondering if Ubuntu tablet is companionable with A7 CPUs such as the ones that were released in the new kindle fire. I know they are compatible with A15 cpus.
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1answer
270 views

mcelog: CPU is unsupported - how to fix it?

Got problem after trying to install samba4. Some of the packages throwing up error: # apt-get install attr -y // NO MATTER AT ALL PART: Reading package lists... Done Building dependency tree ...
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59 views

Why my Ubuntu is so slow? [duplicate]

I have Samsung R610 with Ubuntu 15.04. My computer works very slow. What can I do to speed it? Sholud I clear something (remove some package)? Or is only install driver will resolve problem? It's my ...
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218 views

Computer slow and Ubuntu not using Exchange Ram

I'am using Ubuntu Mate 14.04.2 on my Compaq mini and on certain websites it becomes extreemly low, and at that time looking at the system monitor CPU is always at 100%. (see picture attached) I ...
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1answer
1k views

Difference between ACPI CPUfreq and Intel P-State

Can sombody explain the exact difference between these two drivers, such as the different options they have and how they differ (for example, in the powersave option)?
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101 views

How can I prevent ImageMagick's convert from locking up my system?

I have a decent 4-core i7 computer with 8 GB of RAM and 45 GB of free SSD space. When I run ImageMagick's convert program on a PDF, it briskly consumes vast amounts of resources such that the computer ...
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1answer
99 views

Why does ubuntu consume 25% of the CPUs while beeing idle?

I am experiencing 25% CPU usage on a ubuntu 14.04.03 server which is supposed to be idle. According to htop, load is about 1.0 while the underlying proccess all show 0 to nothing of CPU load. There ...
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143 views

Only one CPU is being used

I am running ubuntu 12.04.5, have an Asus N53sv and I am have the same problem as the post below, but becuase my bios is different I can not apply the same fix. How to fix that only one out of four ...
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4answers
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Ubuntu 15.04 with intel_pstate - low current cpu frequency

I've got Ubuntu 15.04 running on desktop with 6-core 5930K processor, msi x99s motherboard, 32gb ram, ssd and nvidia gtx 980ti. Quite surprisingly, the overall system performance is way lower than ...
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1answer
492 views

Kubuntu 15.04 very slow despite very high CPU usage for every task

It seems that every task that is run on my system uses an excessive amount of CPU power. Monitoring CPU use via conky or top, opening a page in Firefox or searching for something in google suddenly ...
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1answer
5k views

Cores vs Threads: How many threads should I run on this machine?

How many threads should I run on this machine? My lscpu says there are 96 cores. Are those physical cores? What is the maximum and optimal thread that I can run on this machine? http://stackoverflow....
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214 views

intel pstate, turbo always on cpu temp is 60 and without only ~43

I have a problem with pState on my Thinkpad L450 with Intel 5200U (broadwell) + SSD. When I use pstate, the turbo mode is nearly always turned ON and my CPU fan is also always ON because cpu temp is ...
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181 views

High CPU load with only Firefox* open — are my GPU drivers misconfigured?

*Firefox and as well a terminal window. I have two machines, both running Ubuntu 14.10* and Firefox 39. (*I've tried the troublesome machine with 14.04 as well with the same issue described below) ...
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513 views

High CPU with web streaming videos

Every time I start watching some video within a browser (both Firefox 40.0 and Chrome 44.0.2403.157 64-bit with no extensions) the CPU usage gets 100% (according to htop and system monitor) freezing ...
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1answer
654 views

How to turn on AMD Turbo Core for AMD A6 6310 on Linux?

I use Lubuntu 15.04 I've noticed that my processor (AMD A6 6310) works at 1800 MHz frequency and not more, while AMD promised 2,4 GHz with Turbo Core option. How to enable Turbo Core option? $ ...
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258 views

gnome-keyring-d uses CPU too much

I'm using 14.04 LTS and always monitoring how much CPU resources are used by processes. gnome-keyring-d always attracts my attention by using too much CPU - almost 10%. After about 5 minutes OS ...
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103 views

CPUpower sets the frequency by itself

Whenever I try to change the governor or CPU frequency with CPUpower, after 10-20 seconds it starts to go up again.Lets say I set the maximum CPU frequency to 1.5GHz it will go to 1.76GHz and then to ...
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2answers
249 views

How do I diagnose a sudden slowdown

Running a particularly compute-intensive task on my computer (Tecra W50) for more than a few seconds causes it to become very slow. Performance does not return to normal after the task completes. ...
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1answer
238 views

Ubuntu 14.04 - crontab @reboot hang my PC

Trying to resolving the bug for KWORKERS HIGH CPU, as suggested in this answer. I put in my crontab the row: @reboot echo "disable" > /sys/firmware/acpi/interrupts/gpe06 After the reboot, the ...
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1answer
287 views

GUI for monitoring CPU usage (including L1/L2 caches) in real time?

Is there any GUI available in Ubuntu which shows detailed CPU usage, including L1/L2 cache usage? So that while running a custom program, I can monitor the CPU utilization in detail. The default ...
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2answers
441 views

My laptop is seriously overheating

I installed Ubuntu 15.04 alongside Windows 7 on my laptop about an hour ago, and within two minutes of running Ubuntu (both during the Live CD and post-install), my CPU temperatures reach 100°C. In ...
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161 views

Increase processor utilisation of one application/program

I use ClustalX to align few unusually big sequences on my home desktop, this takes more than a week to complete and runs well below the maximum capacity of the machine. The top | grep clustalx gives ...
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1answer
13k views

Should I activate the additional driver: Processor microcode firmware for Intel CPUs for intel-microcode

I have recently noticed that there is an additional driver called Unknown: Unknown here which was not there before: I have already read this, and understand why it is there, but my question is, ...
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2answers
246 views

what could possible take 100% cpu but not show up in (sudo) top

When I start intellij, which loads an "haxe" project at startup, it sometimes happens that intellij hangs loading. I than start htop (also tried top) with "sudo". iotop is also not showing anything ...
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57 views

Debugging kernel running on AMD target from Intel host - how to return control to gdb?

I have compiled kernel 3.13.0-55 on Ubuntu on both AMD and Intel machines. I tried to copy compiled kernel to Intel target but it won't boot with that one. Therefore I have compiled the same version ...
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402 views

Proprietary Intel driver for processor microcode firmware seems to disable overclocking

I installed Ubuntu 14.04 on Asus B85M-G motherboard with G3258 CPU. This CPU has good overclocking possibilities and I was able to overclock it without hassle. Due to minor issues with hibernation and ...
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1answer
587 views

Ubuntu not recognizing all CPU cores

I'm not new to Linux but I'm not an expert either, so bear with me if this is a stupid question. We're running Ubuntu 14.04.2 from a live session USB to test out a new dual CPU workstation. It has ...