How in the world can OpenSuSe be so memory efficient? I’m running 11.3 and Win7 (both 64-bit) on a laptop, and Win 7 uses ~2 GB just to load, even with a lot of services turned off. OS uses 0.53 GB. This is a big deal when you’re running VMs because you want lots of memory available for the VMs…
Wow.
Patti
Hm… it depends on which way you check and interpret the RAM usage - see here:
kalle@hoppers:~> free
total used free shared buffers cached
Mem: 4100928 3974040 126888 0 130336 3083432
-/+ buffers/cache: 760272 3340656
Swap: 1188800 0 1188800
This is the output from a usual desktop session, open programs right now are a mailclient, a Webbrowser, a torrent-downloader, a terminal-emulator and a music manager (plus some “mini-apps”), all within KDE4. Actually the Linux-kernel follows the idea “free memory is wasted memory” because whatever is in the RAM can be accessed by the system right away instead of having to load it from the harddisk - but one has to discriminate between buffered and cached data.
I’m using an Acer Aspire One
my output:
gher1941@linux-nm6n:~> free
total used free shared buffers cached
Mem: 1020552 662920 357632 0 25676 456132
-/+ buffers/cache: 181112 839440
Swap: 2098172 0 2098172
wow…not to shabby!! 
Good memory utilisation is pretty much the case with Linux, though distros vary somewhat in efficiency in using shared libraries. My actual usage, after buffers and caches have been subtracted is under 1GB, even though this workhorse runs lots of programs and services. All the rest is used for buffers and caches. And when you run a non-GUI machine, e.g. a server, you’ll see very usable servers with in tens of MB actual usage.
It also depends on the uptime and the number of apps started since boot of course. My free-output was commanded when the system was already running for two or three days. It usually takes some time until the RAM gets used / buffered / cached fully. Anyway, it is efficient indeed.
I didn’t know about that command - I was just looking at the system monitor applets (in Win 7) and GKrellm (in OpenSuSE). I have VirtualBox running with 2048MB allocated to a session of WinXP:
patti@linux-dv7t:~> free
total used free shared buffers cached
Mem: 8127768 7838348 289420 0 748776 4132140
-/+ buffers/cache: 2957432 5170336
Swap: 2104316 0 2104316
With this same VM running under Win7, the free memory is about 3.5GB, not 5.2GB…