Howdy all. Im going to buy a new box soon, and its been several years so Im a bit overwhelmed. I have some questions about software and the different processor architectures. Some of the software I will install can be had for 64 bit, x86, x86-64, etc. processors. Can someone please explain the differences in all this to me (especially the x86-64 one). Ive always envisioned anything with "64" in it to be much harder to install, but Im starting to think these things may just be different to install, not necessarily harder.

TIA, ChrisR

Depending on what distro you use, 64bit is no harder than 32bit.

Some applications are not available for 64 bit distros yet, like Flash and some Firefox plugins.

You can install any 32 bit distro on a machine with a 64 bit processor, which avoids the above problems and Linux will run just fine.

I use Debian Sid AMD64, and I have not had any major problems (yet).

--Ian

I edited because I hust realized I made a big mistake in what I wrote:

I will be most likely running CentOS 4 (a Redhat clone). If I'm understanding all of this correctly, I would still download the 32 bit install files, and they should install without issue on a 64 bit box? Im guessing it won't be as fast as it could had I installed it using 64?

If you are going to be buying a 64 bit CPU, then you should install the 64 bit version of your distro of choice. At the risk of oversimplifying, the difference between a 32 bit and a 64 bit chip is that the 64 bit can process twice as much data in the same amount of time. (The common analogy is to think of a freeway: in a given amount of time, more cars can move through a 4 lane road than a 2 lane road.) If you are interested in some background history, check out the relevant articles on Wikipedia, as they contain a huge amount of info. Overall, 32 bit is still the standard today, although 64 bit is gaining in popularity. (FWIW, prior to 32 bit, we lived in a 16 bit world, however, the introduction of Windows 95 is what generally could be considered the push that caused 32 bit to enter the mainstream.)

In any case, in terms of the work that's needed, there's no meaningful difference between installing the 64 bit version of your distro vs. the 32 bit version. As IBall indicated there are some minor differences in certain apps (such as the lack of 64 bit version of Firefox) but as he mentioned, you can easily run the 32 bit version on a 64 bit machine due to backwards compatibility. To be honest though, if you plan on just using the regular 32 bit version, there's no real point in spending the extra money to buy a 64 bit CPU.

With regards to terminology, "x86" is just a generic label for any Intel based 386 or higher CPU. (This includes AMD). If you've got an old 386, 486, Pentium, Pentium II, Pentium III, Pentium 4, Athlon, etc, they would all fall into the "x86" category. "64 bit" and "x86_64" are the same thing, and refer to the 64 bit version of the CPU (eg, Athlon 64)