I'm getting a new system soon and I'm considering between getting an AMD Athlon 64 or an Intel Pentium 4. What pratical benefits does using a 64-bit processor have? Anyone here who is using a 64-bit processor? I'll be using GNU/Linux on that system btw.

At the moment there really isn't any benefit. The only benefit is that an 64 bit system will be generally faster than an 32 bit system simply because a 64 bit system is newer than a 32 bit system and the only other benefit is that a 64 bit sytem is ready to take advantage of any new 64 bit software.

There is no real observable difference between a 64 bit and a 32 bit system.

I don't know that I agree that there is no benefit. I have two new AMD 64 bit machines, each with 2G of RAM and high performance disk drives.

I am a bit of a purist, I prefer to compile from source so ...
When I build Apache, Gcc as cross compiler, compile very large projects, etc., I see a very noticible performance gain. 30-40% reduction of compilation times vs faster 32 bit processors.

If you have enough to keep a fast 64-bit machine busy, enough ram to work in and descent drives, it pays. At least for me.

BTW, sorry for the absence. Been abroad for a while working on stuff and had little time for sleep let alone coming here. But, just got back from a week in Jamaica (I know, wrong season) and am a bit rested.