RAM and CPU usage

[mastablasta]

Kubuntu 13.04
APU: E-450 with AMD GPU chip, proprietary AMD drivers
2 GB RAM

it is showing 1.6 GB ram available (i guess the GPU is taking the rest?!)

it all works fast, but yesterday 1.2GB ram was showing as occupied (though swap was not touched). I tried today on boot and it was showing a little over 460MB.
Dekstop effects are the default ones, Nepomuk is disabled.
free-m is showing:

             total       used       free     shared    buffers     cached
Mem:          1602        808        794          0         39        298
-/+ buffers/cache:        470       1132
Swap:         4071          0       4071

What bothers me is that CPU is constantly doing something even if i leave it alone. both cores are occupied 12-14%. is there a reason for this? i am attaching screenshots from a couple of system monitors. would be happy if someone could explain if all is OK and as it should be

Furthermore is that kind of ram usage normal? i have a desktop with Kubuntu 12.04 on it and it uses about 280-300 MB on idle. though i admit that one has 32 bit OS on it.

[Teunis]

I find the CPU use fairly typical, Linux has some daemons running in the background and do things like logging.
Linux will eventually use up most of your RAM, even when a particular application is closed the data will remain in memory until another application would need the RAM.

[tek_heretik]

This might be a bit dated but see the part about 'swappiness'... http://www.tuxradar.com/content/make...d-lighter#null

I'm not sure if it will help or not. When you install most OSes, they detect the amount of physical memory, etc, and attempt to utilize what hardware resources are available to make the OS feel 'snappy', so a lot of 'caching' is normal.

Edit: Re: GPU and memory, yep, if it's on-board, the system 'reserves' a set amount of system memory for graphics processing, in most cases, you can raise or lower the amount set aside for this in the BIOS. Your lappy is most likely set to 384MB video cache.

Edit 2: System Monitor is showing the OS just booted and sitting idle is using 480MB, which actually is a little bit high but nothing to be alarmed about, you also have to figure in Linux 'sees' memory as 1,024KB per MB, that extra 24KB add up in the way RAM is interpreted (a lot of hardware vendors state capacity/size 1000bytes = 1kilobyte, 1000kilobytes = 1megabyte and so on instead of the actual 1024, this is especially true with HDDs, a 1TB HDD should be 1,099,511,627,776bytes as opposed to 1,000,000,000,000). It may be caching more because it is a laptop, instead of accessing the HDD a lot.

[mastablasta]

Well so far the system does work fast (way faster than the preloaded win7 starter). And swap is not used. i set swap to 4 GB as i intend to increase the ram to 6 or 8 GB when i have the money (one slot is empty).

my concern about the CPU usage is does it also use more battery than windows then? i haven't yet emptied it or worked with it long to see hwo well it holds in linux. i did see kernel loads some specific HP parameters. it seems this netbook is well supported (all function keys wrok). the battery is strong and in windows i can manage 5-6 hours easilly with typing and websurfing. if i turn off the wi-fi i can still get about 7.5 hours. i just hope support is the same in the next LTS (looking at you AMD!!!!).

[Teunis]

Another thing, you might see x% of CPU use but because most modern CPU's scale their speed it is at say 800MHz not as bad as the same x% at 2,700MHz.

[tek_heretik]

Another thing, you might see x% of CPU use but because most modern CPU's scale their speed it is at say 800MHz not as bad as the same x% at 2,700MHz.

True, and I also found that AMDs like to 'race' a lot, even when they are not doing much.

[mastablasta]

hmm so best way to see it is to use it and then measure thebatery usage on normal use to see if it's comparable to windows. as here battery is shown in percanage ratherthan esitamed time remaining. ok then. i will see how it goes when i use it more. dind't have the time so far.

[Teunis]

I should have mentioned earlier but have you tried 'powertop'?
It's in the repos.