Trying to figure out why my system gets slow

boast · 2010-10-18 01:13:29

When I am using my computer, everything seems to be fine and fast. But when I go away for a few hours and return, my system is running really slow. So I'm trying to figure out the problem, but top reports my system has little CPU usage-- and System Monitor shows high CPU usage, which feels correct. But I can't pinpoint the applications that would be causing this.

In the screenshots, they were taken one right after another. But in the second one, flash suddenly went 100% cpu usage. But I usually see the first one.

(as you can see, my system was going so slow KDE thought it didn't start, when it actually did)

Last edited by boast (2010-10-18 01:18:50)

Dogmeat · 2010-10-18 01:24:03

I guess it's mainly because of Virtualbox which eats your RAM and your system is swapping which slows down performance of your computer...

ngoonee · 2010-10-18 01:40:23

Yes, once you're in swap your system is going to be slow as those proverbial molasses. Try killing it first. Or just assign less RAM to it.

boast · 2010-10-20 01:13:07

Even after closing vbox, it still wasn't as smooth (like kmenu taking a long time to open up. And the shelf widget being really slow when scrolling or clicking)

But yeah, it seems after running vbox, only a reboot makes everything fine again. Guess its a vbox problem.

ngoonee · 2010-10-20 01:34:15

Please read up on what swap is, how its used, and why just 'closing vbox' doesn't immediately give you back responsiveness.

After that, go and assign less RAM to your virtual machines (do you have more than one running?).

Oh, and mark the thread [solved] please.

gbarnett · 2010-10-20 12:46:27

Its not a problem with VBox but rather the amount of memory you have designated to a particular image. Before you assign a specific amount of memory to a VBox image you shoud profile your system and see how much memory you normally have free and from that you can deduce a relatively safe amount of memory to assign the virtual machine. As others have said the problems start when you start paging memory (you may start to hear your hard drive 'thrashing' quite violently when paging is occurring too frequently) which is always a bad sign.

DIDI2002 · 2010-10-20 14:07:36

I read in another thread that the vboxdrv kernel-module slowed someones pc down a lot. Maybe unloading the module after usage helps?

boast · 2010-10-20 23:26:13

gbarnett wrote:

Its not a problem with VBox but rather the amount of memory you have designated to a particular image. Before you assign a specific amount of memory to a VBox image you shoud profile your system and see how much memory you normally have free and from that you can deduce a relatively safe amount of memory to assign the virtual machine. As others have said the problems start when you start paging memory (you may start to hear your hard drive 'thrashing' quite violently when paging is occurring too frequently) which is always a bad sign.

Well, I have 4 GB of ram (3.6), and I assigned 756MB to a single VM I was running. I guess I should try only 512mb.

DIDI2002 wrote:

I read in another thread that the vboxdrv kernel-module slowed someones pc down a lot. Maybe unloading the module after usage helps?

I'll give that a try next time.

anonymous_user · 2010-10-20 23:47:33

If your VM was only assigned 756MB, I would try finding what (other) applications are using up your (4GB of) memory.

mrinehart93 · 2010-10-21 00:30:01

You're using the i686 Arch, right? Because you're not getting all 4GB of your RAM. Switching to the x86_64 version will allow you to use all your RAM which will help reduce the amount of swapping that occurs.

boast · 2010-11-12 23:43:48

ngoonee wrote:

Please read up on what swap is, how its used, and why just 'closing vbox' doesn't immediately give you back responsiveness.

do you recommend any good reading material to help me solve this problem?

ngoonee wrote:

After that, go and assign less RAM to your virtual machines (do you have more than one running?).

what if I'm not running a VM.

$ free -m
             total       used       free     shared    buffers     cached
Mem:          3707       3357        349          0         20        885
-/+ buffers/cache:       2451       1256
Swap:         2055        441       1613

Last edited by boast (2010-11-12 23:46:38)

Arch Linux

#1 2010-10-18 01:13:29

Trying to figure out why my system gets slow

#2 2010-10-18 01:24:03

Re: Trying to figure out why my system gets slow

#3 2010-10-18 01:40:23

Re: Trying to figure out why my system gets slow

#4 2010-10-20 01:13:07

Re: Trying to figure out why my system gets slow

#5 2010-10-20 01:34:15

Re: Trying to figure out why my system gets slow

#6 2010-10-20 12:46:27

Re: Trying to figure out why my system gets slow

#7 2010-10-20 14:07:36

Re: Trying to figure out why my system gets slow

#8 2010-10-20 23:26:13

Re: Trying to figure out why my system gets slow

#9 2010-10-20 23:47:33

Re: Trying to figure out why my system gets slow

#10 2010-10-21 00:30:01

Re: Trying to figure out why my system gets slow

#11 2010-11-12 23:43:48

Re: Trying to figure out why my system gets slow

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