Ubuntu – Why does Ubuntu Download recommend 64-bit install

14.0432-bit64-bitArchitecturesystem-installation

Why would Ubuntu as a generalized statement recommend its 64 bit “flavour”?

As far as I understand a 64-bit OS can only be installed on a 64-bit hardware (CPU), i.e. 32-bit and 64-bit OS can be installed on a 64-bit hardware, but only a 32-bit OS can be installed on a 32-bit hardware (regardless of the amount of RAM available).

You can see this on the download site:

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EDIT
I understand the difference between 32-bit and 64-bit, and I see the pros and cons. For users with a 32-bit hardware this is not a question of choice. Recommending a 64-bit OS without taking into account the hardware is like recommending petrol over diesel and neglecting the engine. The download site does not check for 64 bit processor hardware, and if detected recommend a 64-bit OS, but recommends a 64-bit OS to all users (with more than 2 GB RAM).

It has been stated that ”manufacturers don’t really make 32-bit systems any more” (Dalton), and that “almost all chips in recent history are 64 bit” (oldfred). This is true at least for processor families in TOP500 supercomputers. So this recommendation simply reflects a trend in industrial production?

Best Answer

Most modern computers come with more than 4GiB of RAM, so you'd need a 64bit OS to use all of this. (Or 32bit with PAE, which is slower) Also, most new machines are using UEFI, and Ubuntu 32bit ISO's aren't UEFI-capable, so here you'd have to go with 64bit

On older hardware, which doesn't use UEFI and/or has less then 4GiB of RAM, it doesn't matter, as long as the CPU is 64bit-capable, which most are.

Other than that, 64bit may be recommended for various reasons:

  • You can run 32bit software on a 64bit CPU (multiarch), but not vice verca. So you may be better off with 64bit when talking about software compatibility.
  • If people don't know the difference between 32bit and 64bit, the should choose the one that will run on the most systems with less problems, which probably is 64bit. Although someone might say that people should know the difference when installing an OS by themselves, I've met at least one person who wanted to install Ubuntu and had barely any clue of CPU architecture ("64bit is better, because it's the greater number" should indicate his knowledge)

There may be other reasons, but these are the ones I can think of now.

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