Why my ubuntu 16.04 LTS suddenly become very slow?

Question

I installed ubuntu 16.04 LTS in Oct. last year on my newly bought HP Envy i7-6700 CPU (x64-based 3.4GHz 4-core 8 -processors, 16 GB ram, 2TB hard drive), it was running OK until just before the X-mas holidays when it became very slow, some times grey window frame. It seems stuck somewhere.

Answer 1

As the other answer, my solution was to disable SpeedStep on the BIOS. I found out that my CPU was running slower. My CPU should run at 1800 MHz, but is was running at 1000 MHz. You can see the current CPU speed using several shell commands, e.g:

lscpu

or:

cat /proc/cpuinfo

It seems there was a problem with my charger, and that made Ubuntu put the CPU into low consumption mode.

Answer 2

I have Ubuntu 16.04 running on a Dell Precision M4800. Today, my system suddenly became extremely slow. Googling the issue brought me here.

I fixed the issue by booting into the BIOS and disabling some of the power management features designed to reduce CPU power consumption when there is little work to do. After rebooting into Ubuntu, my system is running as fast as normal again.

I had this issue with a previous laptop as well-- somehow, it seems like it's possible for Ubuntu to get the Intel CPU "stuck" in a low-power, low-performance configuration permanently.

Answer 3

a box will become slow when it runs low on one of these resources

• CPU
• RAM
• network IO ( bandwidth to the net or any network )
• disc IO ( storage drive overloaded with reads/writes )

when its slow issue this in a terminal window ( ctrl-alt-t ) to display top resource using processes

top

here is the output ... notice load average at right of first row

top - 11:48:11 up 3 days, 8 min,  1 user,  load average: 0.23, 0.39, 0.54
Tasks: 276 total,   1 running, 272 sleeping,   0 stopped,   3 zombie
%Cpu(s):  1.8 us,  0.7 sy,  0.0 ni, 95.2 id,  2.3 wa,  0.0 hi,  0.0 si,  0.0 st
KiB Mem : 16326792 total,  6946732 free,  1726764 used,  7653296 buff/cache
KiB Swap: 16669692 total, 16669692 free,        0 used. 13860968 avail Mem
PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND

17093 stens     20   0 1629772 446180 121904 S   5.6  2.7 137:51.51 firefox

14358 stens     20   0 1390800 420448 113728 S   4.2  2.6   0:35.42 Web Content

 1219 etcd      20   0  639392  28764  12468 S   2.8  0.2   9:24.84 etcd

 1531 root      20   0  470212  72960  56564 S   1.4  0.4  25:49.02 Xorg

 2718 stens     20   0 1266236 112712  61796 S   1.4  0.7  52:15.46 compiz

 2757 stens     20   0  506036  25220  19440 S   1.4  0.2  32:02.48 indicator-multi

 3228 stens     20   0  712920  69960  35624 S   1.4  0.4   2:51.65 gnome-terminal-

 3488 root      20   0  251432  53740  24132 S   1.4  0.3   5:33.92 mongod

13335 root      20   0       0      0      0 S   1.4  0.0   0:01.17 kworker/u16:3

typically when a box is running slow its load average will appear over 5 or so YMMV ... listed under COMMAND is the ordered column of top resource consumers ... when its slow kill off whichever process is slowing it down to confirm you found the bad behaving process ... while running top it will autorefresh every few seconds yet if in a hurry hit the spacebar to force a refresh ... hitting key m will focus attention on showing Memory hungry processes ... to kill off the top most resource consuming process just hit key k from which you can enter options or just hit enter

Above has nothing to do with being slow due to insufficient internet bandwidth. If by slow you mean the browser is slow then a simple check is http://beta.speedtest.net/

Alternatives to top are

htop
atop 
iotop  

Another route to investigate slowness is see if system errors are getting kicked down into system log ... issue

dmesg
dmesg --time-format=iso  #  show timestamp

look for entries (to scroll up in terminal hold down shift then hit key page up ... or roll mouse middle roller button ) important entries are shown in red or appear error related then research on them ... if you are running some rogue driver not tuned to your hardware or fails to play well with others then its conflicting behaviour can manifest in slowness ... to empty out prior entries issue

sudo    dmesg -c

to setup a real time monitor of dmesg issue

watch "dmesg | tail -20"

Here are more logs to examine

cat /var/log/syslog
cat  /var/log/kern.log 

Let us know how you get on - this is certainly solvable ... a major advantage of linux is its efficient use of hardware as well as the ability to adjust everything

Answer 4

Install package called i7z and run it. It will show you whether your cpu is running at full speed and cpu throttling (=lower speed) is not active.

Answer 5

I came here because suddenly my ubuntu is really slow, mouse pointer freezes and jumps, videos jumps and sound clipping. None of these solutions helped me, but I write this here in case someone finds it useful, and if someone who can do something read this. I solved this problem booting with a different kernel version, whenever I boot the last update (for me it's 4.4.0-169), it becomes slow, but when I boot with any previous one it runs nice. Something happened with the new versions.

Answer 6

I did some change in swapiness and cpufreq and it worked well on my Ubuntu.

This is the script I wrote:

#!/bin/sh
#Check if cpufrequtil command exisits in linux system
if ! command -v cpufreq-set > /dev/null
then
    echo "Let me install cpufrequtils for you."
    sudo apt install cpufrequtils
else
    echo "Great you already have cpufrequtils installed."
fi
echo "Let me set your CPU to give better performance."
#Set cpu to performance
sudo cpufreq-set -r -g performance
#Set swappiness to 0 to use maximum RAM and use
sudo echo 'vm.swappiness=0' >> /etc/sysctl.conf
echo "***Please restart to let changes take effect***"

You can download the script from GitHub and run it by triggering command sudo ./fast.sh.