I don't know whether to use Intel x86 or AMD64 image on my computer. I have a 2011 Macbook Air with a Sandy Bridge i7 and Intel HD3000 which is definately capable of handling 64 bits, however, due to the wording on Ubuntu's website. It says that Intel x86 should be used on almost all pcs as well as newer Intel Macs. Since I clearly have an Intel Mac, should I be using Intel x86 image?DownloadUbuntu MATE is currently available for four architectures, PC (Intel x86), 64-bit PC (AMD64), Mac (PowerPC) and IBM-PPC (POWER5) and Raspberry Pi 2 aarch32 (ARMv7).PC (Intel x86) For almost all PCs. This includes most machines with Intel/AMD/etc type processors and almost all computers that run Microsoft Windows, as well as newer Apple Macintosh systems based on Intel processors. Choose this if you are at all unsure.64-bit PC (AMD64) Choose this to take full advantage of computers based on the AMD64 or EM64T architecture (e.g., Athlon64, Opteron, EM64T Xeon, Core 2). If you have a non-64-bit processor made by AMD, or if you need full support for 32-bit code, use the Intel x86 images instead.Mac (PowerPC) and IBM-PPC (POWER5) For Apple Macintosh G3, G4, and G5 computers, including iBooks and PowerBooks as well as older IBM OpenPower 7xx machines.
Intel x86 or AMD64?
ubuntu
Definitely choose 64 bit. You still could launch 32 bit applications, e.g. 32 bit wine. The only downside you could meet is a development of projects that you want to be compiled to 32 bit architecture, but for that case there's a well working workaround with lxc tools.The upside you would get is a better performance. 64 bit code have to be faster, and there are reasons:Function call convention. In general 32 bit code passes parameters through a stack  which is a memory; while 64 bit code uses CPU registers for passing arguments. Even supposedly that CPU cache would reduce the performance hit to the minimal, there's an overhead of copying parameters into a stack.More registers size  a CPU register now could hold two times bigger value.More registers number  64 bit code have an access to two times more number of registers. This means that in cases where 32 bit code have to store a value into a memory, 64 bit code could just leave it in CPU.There's a drawback though that pointers now have two times bigger size, but I tend to think that upsides are still stronger.