memory problem

ramesh14 · 01-30-2009, 05:19 AM

hi
my system privies memory was 2 gb
when i typed this command
free -m

(out put was) total used free shared buffers cached
Mem: 2017 1915 101 0 184 1508
-/+ buffers/cache: 223 1794
Swap: 4094 0 4094

recently upgraded my system memory 2gb to 4gb
now it shows
total used free shared buffers cached
Mem: 3417 322 3095 0 16 180
-/+ buffers/cache: 125 3292
Swap: 2000 0 2000

can any body tell the reason why this system not displaying remaining 583mb.

ilikejam · 01-30-2009, 06:03 AM

I'm guessing you're on a 32bit PC, in which case you'll never see that missing memory. Problem is that the memory in your video card, and IO for various components is mapped onto the top of the 4GB RAM space available to 32bit architectures, effectively hiding that RAM. Same thing happens on Linux and Windows, and any other OS on a 32 bit x86 processor.

Dave

Quakeboy02 · 01-30-2009, 11:42 AM

If you have a PAE capable processor, then switch to a PAE enabled kernel. It may be known as hugemem or 64G or something like that. That will get you the rest of your memory, but I believe there may be a small (~3%) performance penalty.

lazlow · 01-30-2009, 12:24 PM

Even if you have a 64bit machine running a 32bit OS the above applies. If you switch to a 64bit OS (assuming 64bit machine) this issue goes away.