[SOLVED] Why is my Debian computer only using 2GB RAM? (i686 2013 Macbook Pro running Debian KDE)

theOakBaron · 02-03-2018, 08:29 AM

The computer originally had 4GB of RAM in it, and I thought that maybe half it had been damaged somehow. The computer is relatively old, after all. I got 4GB of working ram and popped it in but "vmstat -s" command still only shows 2GB of total RAM. Why is this and can I fix it?

Lysander666 · 02-03-2018, 09:02 AM

32 bit cannot address 4GB as far as I remember.

hydrurga · 02-03-2018, 03:01 PM

Quote:

Originally Posted by Lysander666

32 bit cannot address 4GB as far as I remember.

Yes it can.

https://www.linuxquestions.org/quest...-limit-707762/

However, if the kernel is PAE-enabled and the CPU supports it, which almost all do nowadays, this rises to 64GB.

https://en.wikipedia.org/wiki/Physic...xtension#Linux

It sounds to me as if the OP's problem is hardware-related.

jsbjsb001 · 02-03-2018, 03:44 PM

Quote:

Originally Posted by theOakBaron

The computer originally had 4GB of RAM in it, and I thought that maybe half it had been damaged somehow. The computer is relatively old, after all. I got 4GB of working ram and popped it in but "vmstat -s" command still only shows 2GB of total RAM. Why is this and can I fix it?

While I can see you have marked this thread as "[SOLVED]", I have to agree with hydrurga.

Also, if it's only showing 2GB when you run the command in the link below, into the "Open Firmware interface" shell, then it's probably the RAM that has gone bad. I would check that anyway.

https://superuser.com/questions/3975...mware-ram-size

cynwulf · 02-03-2018, 04:18 PM

Quote:

Originally Posted by theOakBaron

The computer originally had 4GB of RAM in it, and I thought that maybe half it had been damaged somehow. The computer is relatively old, after all. I got 4GB of working ram and popped it in but "vmstat -s" command still only shows 2GB of total RAM. Why is this and can I fix it?

Unless you're running a very old release of Debian, then a 686 kernel will have PAE enabled (686-pae). The old 686 non-PAE kernels were removed, probably around the squeeze (6.0) release as I recall (from that point on you had to install the 486 kernel to get a non NX/PAE kernel).