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So I have a machine with AMD E-300 ( ), and 4096 MegaBytes of RAM memory, 3712 MB usable, because the integrated GPU takes 384 MB. What should I use, considering that it is an x64 CPU? Should I go with the x64 version of Xubuntu/Lubuntu, or with the 32bit/x86 one? Would my machine perform better with the x64?

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marked as duplicate by Mateo, Kevin Bowen, Mik, Eric Carvalho, Seth Mar 28 '13 at 0:10

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Why not just try them both and judge for yourself? – Rinzwind Jan 25 '12 at 15:51

64-bit utilizes large amounts of memory more efficiently that 32-bit. So I would go for x64.

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Agreed (+1) ............. – One Zero Jan 25 '12 at 15:50
So now we need someone to add an answer to use 32 and we got ourselves a race >:) – Rinzwind Jan 25 '12 at 15:51
4GB is not a large amount of memory... See my answer for more details. – Veger Jan 25 '12 at 16:06

As you can see, the debate rages =)

If you have a 64 bit processor you should start with a 64 bit OS, you are simply going to get better performance. If you google search you will find the benchmarks to back that ;)

Take note: most of the benchmarks are old as 64 bit has been on parity for long enough that the vast majority of people advise 64 bit (and so fewer people are publishing benchmarks).

64 bit Ubuntu has been on parity with 32 bit for several years and you are no more or less likely to have problems with one vs another.

If you do run into the increasingly rare problems with 64 bit Ubuntu you could downgrade to 32 bit.

In terms of RAM, you can use up to 64 Gb RAM with a 32 bit PAE kernel, so the size of your RAM does not really enter into the equation, except that 64 bit will user your high ram more efficiently.

Understand "high ram" is relative, but at a lower level 4 Gb is "high ram". If you wish to know the technical details, see the kernel discussions / documentation.

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I would go for 32-bit.

64-bit does not give real advantages, except for being able to address more than 4 GB RAM. As you have 4GB 32-bit is not a problem.

Disadvantage of 64-bit: data fields use twice the amount of memory: for example integers become 64-bit wide instead of 32-bit. So effectively, the available amount of memory drop by two (assuming everything is stored as an integer)

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It's not correct. x86_64 is far more than just 4GB addressing (since 32-bit x86 already has capability to address 64GB of RAM). One example is (more than) double the number of registers, which makes compute intensive programs run much faster – Lưu Vĩnh Phúc Mar 10 at 9:41
Hardware-wise you are right: But AFAIK 32-bit applications cannot address more than 4Gb memory. – Veger Mar 10 at 13:13
of course it can only address 2-3.5GB of memory. That's one of the reasons why 64-bit applications are better. They have more address space to get around for various purpose like memory-mapped file. They have more registers and newer default SIMD instruction set... In 95% of the benchmarks 64-bit apps run faster – Lưu Vĩnh Phúc Mar 10 at 15:41
Which is what I wrote :) – Veger Mar 10 at 21:14
it's not actually correct. Most variables in a program still be the same size. Only pointers are larger. A 64-bit program will use ~30% more memory on average, not twice the memory, but run 10-15% faster – Lưu Vĩnh Phúc Mar 11 at 3:01

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