I just installed openSUSE 11.2 on mt Lenovo T61 (3GB RAM) and everything worked perfectly but when I clicked on My Computer and saw that the system is using 2.5GB or my 3GB RAM. I was surprised because it was a plain installation and nothing was running, no browser no IM.
I installed kubuntu 9.10 and it was using 600mb only, If anyone of you know why its eating so much of memory it would be helpful because I dont see that Kubuntu is as good as openSUSE in terms of the OS usability (especially Yast).
You might be reading it wrong actually, heres my readout in my computer (sysinfo)
Total memory (RAM): 2.0 GiB
Free memory: 80.1 MiB (+ 1.5 GiB Caches)
Free swap: 2.4 GiB
Sure
Total memory is the memory you have in total
Free memory is apparently the memory you have used up so far
And swap is swap.
swap memory is like emergency memory.
Anyhow I think you should ignore the readout from My Computer (sysinfo) as honestly i dont think it reports memory usage accurately, instead you should use the kde system monitor.
Located in system> monitor system monitor.
Info center is a little more accurate too
The point is Taralkeda (and you too probably…) have lots of cache. Cache is memory which is ‘used’, in the sense that Linux is efficient at leaving your memory filled up with stuff that you’ve used recently, in case you end up using it again. It isn’t ‘reserved’ though, and if it suddenly is needed, it’ll be emptied quickly.
I don’t know why Kubuntu doesn’t report the same - it’s almost certainly doing the same thing. They probably patched it to avoid confusing people, which doesn’t make much sense to me…
Try running ‘free’ in a terminal to see a good breakdown. And you can check it’s all working OK by actually telling it to drop the caches - note that this doesn’t actually have any advantage, it’s just an experiment to reassure you that the memory isn’t really ‘gone’.
You can even install ‘preload’, which will fill your ram up before you’ve even started running things. It does slightly slow down the system at boot, but will cause things to run more quickly once you’re up and running.
If you don’t want to use it and wish to save it, shut down the computer, open the case. remove 2.5 gigs of memory, put it in a safe place perhaps on a shelf somewhere where it can not even be seen by the computer. You can then rest assured that your system will not use the memory and you can look at it on the shelf with satisfaction that it is safe.
Ah so “free memory” reads out cache sorta then in sysinfo, i wasnt sure what it read out.
I know how linux uses memory sorta, so I sorta got the gist of the readout.
But I dont pretend to be an expert though
Well I used free at console and its showing that more than 2GB is used and when I do “top” I see the main memory hog is X, which is very high compare to kubuntu
He’s looking at VSZ, not RSS which means you’re looking at the virtual address space used by Xorg, NOT the real memory consumption (which on my 11.2+nVidia+KDE) hovers at 70-80MB.
Chrysantine can you please explain me what you are talking about? because in your screenshot I can clearly see that the used memory is 1.5 GB and free memory is 700MB
Anyway, as previous posters have explained - Linux, like all modern operating systems, uses ALL available memory as cache, storing frequently used information and it releases this memory dynamically as the system needs it - for example if you were to start Firefox, it would release the amount of memory in the cache to be used by Firefox and the data it needs. Unused memory is wasted memory.
If you look at my copy paste, the only important thing is the second line, second number, in this case; 14163584 - this number indicates the amount of FREE memory without taking cache/buffers into consideration. This is REAL available memory to the system.
As covered in another thread, use the ‘<’ key to sort on RES in top(1), ignore the virtual memory sizes as the kernel allows over-comitting of memory to support programs which allocate “sparse” address spaces.
Xorg looks worse than it really is, because it’s use of things like the graphics card memory tends to get booked to it.
If Kubuntu 9.10 manages to conserve much memory somehow on same architecture would be interesting, but care must be taken to make sure similar programs are running.
Thinks like the ‘updater applet’ do use more than you’ld expect (9 MiB) when I last looked.
Swap space should be used, to allow written but rarely used data to be evicted to disk, so there’s less need to through program pages away, which tends to induce a lot of disk seeking, after you’ve been away from PC.
