Does Ubuntu Desktop 32Bit Support more than 4GB Memory with default installation?
Does Ubuntu Desktop 32 Bit support more than 4GB memory WITHOUT changing anything (Without having to activate PAE via compiling kernel or anything similar). Will installing the 32 Bit Ubuntu on the machine be enough to detect the additional memory automatically. If yes, will this work if I add more than 4GB with a 32Bit Ubuntu already with 4GB Ram.
One example would be to have 8GB Ram with Ubuntu 32 Desktop.
My Motherboard supports up to 8GB RAM and it has 32 Bit and 64 Bit support (It is the intel DP35DP)
Ubuntu 10.04 and newer should support PAE out of the box, and most processors produced in the last twelve years do too, so in theory it should work fine.
If you're trying to install Karmic or older, you may need to enable PAE yourself, as per this wiki article.
It may also be necessary to switch certain options in your BIOS, such as "Software Memory Hole".
The information in this wiki article may be of use to you as well:
A 32-bit computer has a word size of 32 bits, this limits the memory theoretically to 4GB. This barrier has been extended through the use of 'Physical Address Extension' (or PAE) which increases the limit to 64GB although the memory access above 4GB will be slightly slower.
From the Ubuntu Community Documentation: Enabling PAE
Both the CD and DVD installer of Ubuntu 10.04 automatically installs the PAE enabled kernel if it detects more than 3 Gb of available memory. In the case of the liveCD, a working network connection is required, since the PAE enabled kernel packages are not present on the CD.
Physical Address Extension (PAE) is a feature that allows x86 (32-bit) processors to access a physical address space (including random access memory and memory mapped devices) larger than 4 GB (theoretically upto 64GB).
If you use the PAE enabled kernel, then yes. I am using 32-bit with 8GB of RAM right now. I think PAE was also made the default for 12.04.