I noticed always a big difference in memory usage as reported by (1) Conky and (2) free (a classic command line tool).

Directly after booting, according to "free", my N900 uses already almost all of its RAM and some 100 MB swap space. After 11 days normal usage, I get about 200-250 MB swap space used, while RAM is always nearly full.

Conky reports about 170 (+/- 20) MB RAM used, both after booting and also now after 11 days usage.
Which one is more correct? Or do both programs use different definitions of "used RAM"?

(Remark: Both programs agree about swap space usage.)

Thanks for a good explanation.

There's no useful measure of "free" ram, and used ram isn't necessarily total-free. "Free" really means unused, and there should be a minimal amount of unused ram. Unused ram is wasted ram.

Something more useful than free ram though, would be a measure of available ram. Ram that can be quickly made available without and paging. This would approximately be free+buffers+cached minus executable and library files in cache, though if a file like that is actually not used, then that would be available too.

In short: there's really not any good measure

conky wins then
just use the variable "memeasyfree"
"Amount of free memory including the memory that is very easily freed (buffers/cache)"


oh, you need to post your relevant lines from the .conf file if you are asking stuff like this. for all we know, it is reading the complete wrong thing and labeling it "ram"