I do have the AMD Athlon 64 Processor.

Will I really notice any difference between running the two different versions? Performance or otherwise?

The reason I asked is because I ran the AMD64 version of another distribution and had tons of trouble with it while the i386 version ran fine.

Thanks much!

I've been running Fedora Core x86_64 on an AMD64 for two years now, and haven't had any problems (using it both as a desktop and a server). If you are having a problem, maybe you should try a different distribution?

Oh, I've had no trouble at all with SLED. It's the first distro I've ever installed where EVERYTHING just.. worked... with no tweaking required. I have the AMD Athlon 64 processor.

I'm running the i386 flavor and I'm just wondering if I ran the AMD64 flavor, if I'd notice any better performance.

I love my SLED!

You will notice the difference when you run applications that can benefit from 64-bit operation. For example, I noticed dramatic improvement with ffmpeg encoding in 64-bit. Day-to-day desktop operation will of course not change - it's not CPU intensive and doesn't require moving/processing large amounts of data.

While you can run 32-bit applications if you need to on a 64-bit distro (thanks for not supporting 64-bit, Macromedia Flash), you can't run 64-bit applications on a 32-bit distro.

I have both flavours of machines (amd athlon 3000+ 64 bit and amd 2000+ 32 bit).
Memory intensive operations (videoencoding, raytracing and so on) are much faster in 64 bit. It's the major reason I prefer linux at the moment above the windows video programs. Of course supposed you are not crap in physical memory!
The (free) programs have limitations, but the system is running very smooth. It's a pity that some commercial videoprograms for linux as mainactor don't have a 64 bit version.
But in the free open source there are a lot of very good 64-bit programs: blender (raytracing) avidemux, mandvd, kino, cinelerra (all video)...

Thomas