Make Ubuntu fully use 4 GB to 8 GB memory

Solution: first, install the 64-bit Ubuntu system. The most thorough solution is to improve the system performance. But the fatal disadvantage is that "most software does not support 64-bit"-the same as 64-bit Win7. Second, you do not need to change the Ubuntu system or the kernel. That is, the method I used. 1) enter the following code on the terminal (install the PAE kernel): sudoapt-getupdatesudoapt-getinstalllinux-headers-ser

Solution:
First, install the 64-bit Ubuntu system. The most thorough solution is to improve the system performance. But the fatal disadvantage is that "most software does not support 64-bit"-the same as 64-bit Win7.
Second, you do not need to change the Ubuntu system or the kernel. That is, the method I used.
1) enter the following code on the terminal (install the PAE kernel)

Code:
Sudo apt-get update
Sudo apt-get install linux-headers-server linux-image-server linux-server

2) restart the machine

Effect:

Code:
Www.linuxidc.com @ www.linuxidc.com :~ $ Free m
Total used free shared buffers cached
Mem: 3968936 3724856 244080 0 53352 3242492
-/+ Buffers/cache: 429012 3539924
Swap: 4087804 0 4087804

We can see that all 4G physical memory is used.