Not using RAM and Swap much ?

ruwach · 06-11-2004, 06:36 AM

Hey there,

i have a frankenbox that i built with debian and kernel 2.6.5, i have a 900 mhz athlon and 251 megs of RAM, i also have a 288 meg swap file that was allocated automatically by the debian installer.

My issue is this. According to GKrellm, my RAM never dips below 156 free, and swap never below 180 free. Even when the processor is at 99%. Like when compiling software or compressing audio. Am i not using my RAM to its full potential, or is there some that just isn't being used? is it because my Hard Drive is old (6 gig from about 1998) ? or am i miss-reading what GKrellm is telling me?

if there is something i can do ( been thinking about upgrading my HD anyway ) to speed things up here?

i am pretty sure the RAM i have is fine, i ran memtest-86 for about an hour and everything seemed ok.

please let me know.....

fancypiper · 06-11-2004, 07:09 AM

I usually run memtest for a couple of days if I suspect bad ram using the whole shebang of tests. If you aren't crashing, your ram/swap are probably perfectly OK. You don't really need that much swap.

I have to do massive data movement to touch swap on my boxen.

Isn't it neat how efficiently Linux uses memory compared to the popular OS?

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

hw-tph · 06-11-2004, 07:26 AM

I believe gkrellm displays the memory in active use. Buffers and cache are not displayed. Type free -m at the shell prompt and you'll see something like this:

Code:

             total       used       free     shared    buffers     cached
Mem:           186        183          2          0         48         60
-/+ buffers/cache:         74        112
Swap:          376          0        376

The "mem:" line displays the total amount in use while the second line displays the amount of active memory use. As you can see here I've got about 2MB of really unused memory - most of the memory is used as in-RAM buffers and cache. The second line ("-/+ buffers/cache") displays the buffer adjusted line with only memory that is in active use.

Håkan