View Full Version : [ubuntu] Laptop does not detect all 4GB RAM

January 18th, 2009, 08:51 PM
Hi there

I have installed Ubuntu Intrepid on my work laptop (HP 6530p). I then discovered that it only detects about 2.9GB of my total of 4.0GB primary memory?

Can Ubuntu only detect 3 GB of Mem?


January 18th, 2009, 08:55 PM
in 32bit mode yes, 64bit can use the full 4gb.

January 18th, 2009, 08:56 PM
32-bit operating systems can only address 4GB of RAM. Depending on your install/motherboard, that extra 1GB is to other things like memory mapping, etc.

Install the 64-bit version to see all 4GB.

January 18th, 2009, 09:05 PM
Hello, if you have 4gb, 32 bit will only detect 3gb but will still use the 4gb, but 64 bit will show all 4gb.
Hope this helps

January 19th, 2009, 10:41 AM
So it will still be able to use the full 4GB, but wont see all 4?

Thanks! For some reason I cant give you a thank you on the forum...


January 19th, 2009, 02:36 PM
This is a frequently asked question.

If you're running a 32-bit operating system (Ubuntu, Windows, or whatever else), you will at most be able to use 4 GB minus an amount reserved for communicating with I/O devices and your video card.

If you're using a 64-bit operating system, you will most likely be able to use more of the 4 GB. Look if your BIOS has a "memory remapping" setting. This will move the addresses reserved for devices out of the way so that a 64-bit OS can use (almost) the whole 4 GB.

My laptop running 64-bit Ubuntu can see about 3.9 of the 4 GB.

If you have more than 4 GB, you'll need a 64-bit OS (or a 32-bit OS with PAE (http://en.wikipedia.org/wiki/Physical_Address_Extension) enabled, such as 32-bit Ubuntu Server).