memory full, computer slow
 

Hey guys,

I've been using linux mandrake for about 3 years now and just yesterday i installed suse 9.0 Professional.

I like it so far except for one problem:

My memory is full, i have 512 mb ddr ram and i only have between 10 mb and 200 kb left of free memory.
i checked my processes with 'top' and there didn't seemed to be anything unusuall about the processes.

this is making my computer very slow, and it produces quite some heat when it's running all day long.

It would help me alot if someone knew the awnser or a tip that would get me further in this.

My computer:
Pentium4 3ghz 800mhz FSB
Asus P4P800 MB
512 MB ddr RAM
ATI Radeon 9800Pro 128 mb

How did you check your memory usage? Linux will cache a lot of RAM, but only use some of it. For instance, the top command shows 502 of my 512mb's being used, but in reality Im only 'using' 110mb's. Like 390mb's of that ram is cached. Try using gkrellm or something to see your mem usage. It will only show what you are actually using. Otherwise, take what top shows as used, and subtract buff & inactive. Then the remainder is ram actually in use.

As far as the heat, also try gkrellm. If all your monitors look normal (cpu, disk, etc) then the heat is prob a hardware problem. If you see the cpu @ 100% when its sitting idle, then use top to find out what is using all those cycles.

You can see the actual memory usage by typing "free -m" at a command prompt:

This example shows that I have 391MB free (-/+ buffers/cache line) out of 503MB total and I'm using 1MB swap space out of 517MB total. If you really think you are running out of physical memory, check the used column on the swap line. If the swap used amount continues to increase, then you are running out of memory, otherwise the memory is being stored in the buffers/cache and is available when needed.

Speck

# Memory and swap information
cat /proc/meminfo
free
An article: Tips for Optimizing Linux Memory

From what I understand Linux generally (i use RH but it may be across the board) that the OS will use the memory up so to speak so that eventually it will show that you have very little left... but in fact it only clears the memory when it needs it that way its not using up resources clearing the memory without reason. Command like top will show that the memory use is slowly increasing which is perfectly normal because when it gets almost used it will clear the cache on it.

Right??

512 ram thats nor bad i am running mandrake 9.2 on 64mb of ram

i mean not, off the subject does anyone know how i can change my signiture

using the free -m command i had this as a result:
total used free shared buffers cached
Mem: 501 374 126 0 51 100
-/+ buffers/cache: 223 277
Swap: 1019 0 1019

So if it's not my memory then i wonder why my computer is so slow.

After installing gkrellm i found out i have 270 mb free memory, however the cpu is busy at an average of 80% while i'm not doing anything

top - 13:11:18 up 37 min, 4 users, load average: 0.44, 0.32, 0.22
Tasks: 91 total, 1 running, 90 sleeping, 0 stopped, 0 zombie
Cpu(s): 1.2% user, 40.1% system, 0.0% nice, 58.7% idle
Mem: 513360k total, 504388k used, 8972k free, 56488k buffers
Swap: 1044152k total, 0k used, 1044152k free, 184440k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2296 root 15 0 50652 40m 3192 S 5.6 8.1 4:20.30 X
4039 me 16 0 7776 7776 5708 S 1.0 1.5 0:05.37 gkrellm
4093 me 16 0 952 952 744 R 1.0 0.2 0:00.56 top
2451 me 16 0 176m 43m 21m S 0.7 8.8 2:29.77 kdeinit
4082 me 15 0 152m 19m 14m S 0.7 4.0 0:01.81 kdeinit
2399 me 15 0 152m 20m 14m S 0.3 4.0 0:04.54 kdeinit
2890 me 15 0 13344 13m 8532 S 0.3 2.6 0:13.15 xchat
1 root 15 0 256 256 220 S 0.0 0.0 0:04.48 init

according to 'top' it isn't doingh much either yet the cpu monitor in gkrellm shows it's very active at 80/90% :confused:

Well, if gkrellm shows 80% then it is likely 80%. Try ps -aux to get a complete list of processes and see if there's anything unusual there.

Also, check to see if DMA is enabled for your hard drive. When I was using kernel 2.4.20 I couldn't get dma to stay on. The aftereffect was extremely high CPU usage during any disk activity.

Try this to check drive speed: hdparm -Tt /dev/hdX (where X is your drive, prb: hda)
And this to see drive settings: hdparm -v /dev/hda

The usercp button up near the top. Then, edit profile.

it's fixed :)

i'll tell ya what the problem was, i have a pentium 4 3ghz with hyperthreading (or something like that) anyway, suse thought they were 2 cpu's and so installed the smp kernel instead of the normal one.

i tried to change kernels without having to reinstall but at bootup it gave an error so i had to reinstall suse but that's ok cuz now everything is working as it's supposed too