PAE Kernel confusion - 4 GB RAM exactly

[KirkD]

I've been reading up on PAE kernels and haven't found anything difinitive regarding the 4 GB limit. So, rather than confuse myself, I'll ask here.

I have a Dell Inspiron 1720 with 4 GB RAM. When I go into the BIOS, it explicitly states 4 GB of RAM available. I have F10 non PAE running right now, and I haven't checked with 'free' but I do know that when I run Gnome's version of Task Manager (I forget the actual name, but it tracks the processor usage, memory usage, and network traffic graphically) the memory pane says 4 GB. (I'll double check this later and post a snapshot.)

When I originally installed, I had the PAE kernel going, but I could not get wireless working, and I've read many, many issues related to nVidia drivers and Compiz under PAE kernels. Right now everything is cranking along nicely under F10.

If my BIOS says 4 GB, do I really need the PAE kernel? What test can I do in F10 to verify full memory access? I've also considered the 64-bit version, but I've read conflicting reports on how well that works. It seems people experience various problems. (That might be a good test for my experimental partition, eh?)

-Kirk

[William Haller]

cat /proc/meminfo

See if total memory is 4 GB. I don't think you need PAE unless you go beyond 4.

Alternatively, run top or htop. Either will show your total memory as well as information about how it is being used.

If you're running KDE, you can also run kinfocenter to see a graphical version.

[KirkD]

Will,

I'll give these a shot when I return home and report back. Thank you!

-Kirk

[KirkD]

So, when I execute free -k, I get:

             total       used       free     shared    buffers     cached
Mem:       3893220     678856    3214364          0      19520     275780
-/+ buffers/cache:     383556    3509664
Swap:     25511200          0   25511200

I see the same 3893220 when top is running. And, when I run System Monitor in Gnome, I see the memory section at 3.7 GB.

It would seem that I have all but 200 MB accessible. I may try to play around with PAE under an experimental partition, but I'm not doing badly now.