UbuntuHelp:32bit and 64bit
32-bit and 64-bit
Most computers run in 32-bit mode. Processors capable of running 64-bit mode are AMD's Athlon x64, FX, X2 processors, Intel's Itanium and Xeon, Intel Core 2, Pentium D, some versions of Pentium 4 and Celeron D. For AMD processors, if the processor supports AMD64, and for Intel processors, if the processor supports EM64T (which is Intel's version of AMD64), the processor is capable of running in 64-bit mode.
- What about "G5" PowerPC chips? Or SPARC64, MIPS64, etc. (Note: Linux works on EVERYTHING! :) )
What is it?
32-bit and 64-bit are really the size (or width) of a chunk of memory (more accurately, the memory registers) in the computer. A 32-bit computer has a word size of 32 bits, this limits the memory to a very very large number (4 GB of physical ram in practice). A 64-bit computer will handle a literally enormous amount of memory (about 128 GB of physical ram). We are moving towards a world where information is stored in a terabyte. A few of these will store all the programs of your favourite TV station for a number of years. When you are moving this amount of data and compressing it to store it more efficiently, then you need the extra power 64-bit allows.
Which is better?
A 64-bit processor is the way of the future, and it is worth mentioning that AMD's 64-bit processors function fine in a 32-bit environment. One might still recommend staying with 32-bit software because the 32-bit software has more support, but that is changing. Within 10 years one would expect most computers to be 64-bit, however one might believe that between now and then the average person will have another 2 computers (one every 5 years). The bottom line is that for free software it is not that important. Code can be converted between the two because it is source code so that most things 'just work'. The unfortunate thing is that it is actually a little tricky converting some programs from 32-bit to 64-bit and therefore some programs cannot run in native 64-bit mode. They can run in an emulated mode but this will be a little slower. There is even the case when code that works in 64-bit actually runs slower because of the magic in the processor differences. On processors that support AMD64 or EM64T, performance might be slightly higher in 64-bit mode than in 32-bit mode. The (technical) reason for this is that in 64-bit mode, the processor has more and wider registers available, which means that programs compiled for 64-bit mode can run more efficiently.
How to make 32-bit work on a 64-bit machine
At this time, those with a 64-bit processor have the option of installing the 64-bit version of Ubuntu. Not all software is available in the 64-bit environment. In particular non-free items are usually 32 bit. For example the Flash plugin is a 32-bit program. Some programs can be run in the 64-bit version of Ubuntu by using the 32-bit libraries. You can install ia32-libs by using your favorite package manager. Another option is to create a 32 bit environment with chroot