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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)

Luis Alvarado
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7 Answers7

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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.

oKtosiTe
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9

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).

Sid
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6

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.

dobey
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4

As in Ubuntu documentation:

  • Ubuntu 12.10 (Quantal) and onwards: The generic default kernel already has PAE enabled.
  • Ubuntu 10.04 LTS (Lucid Lynx) to Ubuntu 12.04 LTS (Precise): Both the CD and DVD installer of Ubuntu 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.

reference: https://help.ubuntu.com/community/EnablingPAE

So you don't have to install kernel or compile it. Just use the alternate installer CD; or Ensure you are connected to interent while installing if you prefer the live desktop CD

Mohamed El-Nakeep
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2

if you installing ubuntu 32bit with 4gb, it will detect automatically, and installing linux kernal pae. so you can use your 4gb ram

but if you upgrade to 4gb ram, you need to install linux kernel PAE.

this is a good link : https://help.ubuntu.com/community/EnablingPAE

:D

Eko Kurniawan Khannedy
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pae-kernel is default in 12.04, so you could use up to 64 gig (if your motherboard allows that ;-)

gemue2010
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PAE above is the best route. For your information, This week I took advantage of cheaper UK 8Gb RAM (£20.00!) modules for my current AMD X2 Dual core with 4Gb DDR3 (1333) memory, replacing the 2 modules with one single 8Gb, but found then I only had some 3.7Gb in memory using (the System Tool). A quick read here on askubuntu and the said above article https://help.ubuntu.com/community/EnablingPAE using PAE, a quick install via Terminal, and a reboot, then gave me 8Gb.

For the present, I'm only running 11.04 on 1 of 3 comps (others run 12.04), but will upgrade to the latest when time prevails. I merely wanted the memory to work now and PAE was not installed on my 11.04. It took me as long as it takes to download via Terminal as in the above help "Enabling PAE manually" section of the article. If PAE supports upto 64Gb as it says, then I'll take the 16Gb RAM route.

I suggest anyone looking to upgrade similar at 11.04 stage, follow the above.

Paul B
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