Memory limit on 1G RAM machine?

SlowCoder · 03-27-2007, 08:37 PM

I've read on these forums that there's a default 880MB RAM limit on Linux, even with the newest 2.6 kernels.

I ran free on my machine and got the following:

Code:

             total       used       free     shared    buffers     cached
Mem:       1024760    1004372      20388          0     164920     371072
-/+ buffers/cache:     468380     556380
Swap:      2031608          0    2031608

The kernel is still stock.

1. Based on this, it shows I've got 1G RAM, with 556MB free, right?
2. Am I limited to the 880MB, even though it recognizes the full 1G?

Quakeboy02 · 03-27-2007, 09:05 PM

If your distro has a HIGHMEM kernel available then use that. Otherwise, you're going to have to build your own in order to use that memory.

SlowCoder · 03-29-2007, 12:17 PM

Quote:

Originally Posted by Quakeboy02

If your distro has a HIGHMEM kernel available then use that. Otherwise, you're going to have to build your own in order to use that memory.

How do I go about checking if I've got it?

Quakeboy02 · 03-29-2007, 02:28 PM

I should have looked at your post more carefully. Your kernel recognizes the memory, so you're good to go.

jay73 · 03-29-2007, 03:24 PM

Stick with what you've got. I didn't select any special kernel and it still recognizes my 2GB of RAM. Also, I think that the HIGHMEM kernel is actually for 4GB RAM and up although I may be wrong there.

trickykid · 03-29-2007, 04:19 PM

It's going to look something like this in your .config file for your current kernel configuration:

# CONFIG_NOHIGHMEM is not set
CONFIG_HIGHMEM4G=y
# CONFIG_HIGHMEM64G is not set
CONFIG_HIGHMEM=y

There's HIGHMEM and HIGHMEM4G. HIGHMEM handles over 1GB, HIGHMEM4G handles systems with over 4GB of memory..

From your output, like mentioned before, your kernel is supporting your 1GB of ram. I wouldn't worry about the HIGHMEM4G unless you plan on adding over 4GB or more..

SlowCoder · 03-29-2007, 08:08 PM

Cool. I'll probably add another 1G sometime, to get the dual-channel out of it ... and so I can say I've got 2 Gig!

Thanks guys!