What is the difference and which would be better for first timer?

It will depend on who you talk to. For home users, there isn't any real performance gain from the 64bit platform. 64bit would be better if you were doing a lot of calculations or SQL queries. It would also be necessary if you would need more than 4GB of ram, but I doubt you do. Since the 32bit is more tested, I'd recommend sticking with it.

musicman_ace Thanks for the advice, that's probably what I will do.

technically isnt 64 bit supposed to be twice as fast?

also for render time, would the 64bit be a lot faster?

Only for *very* specific memory transfers and memory operations, and even then it won't be quite twice as fast, and that speed improvement does not extend to operations like file I/O or even displaying stuff to your screen. You'd notice an improvement in render farms, large project compile jobs, large DBMS servers, and things of that nature, where small percentages in performance will save hours to days, but not for most things you would do, like gaming, surfing the web, etc.

It depends on the specific algorithms use, and how well the code is optimized to take advantage of 64-bit words, and also whether or not you were hitting the 4GB memory limitation of 32-bit platforms.

32-bit is better at the moment as there are no 64-bit versions of many popular software.Mandriva LE 2005 comes in 3cds for 32-bit and only in one for 64-bit.

the athalon64 has both 64bit and 32bit cores if you run a 32bit os you only use the 32 bit core if you run a 64bit os you run the 64bit core and you can run 32bit apps on the 32bit core. From bchivers' sig it looks like he has an athalon64 why pay for a 64bit chip and never use it?

I was thinking about that when typing my previous post. I know Windows does that, but I am not sure if you could install i586 apps on x86_64 platform.If you can, its
great ! But can you???

The question was "Which is better for a first timer". I have an Athlon 64, and I've tried all the 64bit distros. The only one that seems reasonably stable is Gentoo.

A previous poster noted that there isn't a lot of 64bit apps, I disagree a little on this. If you compile the source, like gentoo, then your apps are 64bit. There reason to buy one now and run a 32bit platform is simple. When the 64bit world becomes more stable, you'll be there to welcome it. The price of an Athon 64 is equal or less than Intel chips. In certain cases, the 64bit word can improve speed.

you'll get no argument from me on gentoo being best, but I'd say that suse_x86 is at least as stable as windows and, yes you can run an i586 app in 64 bit linux on the athalon64.