Right now AMD is probably one of the best choices for upgrading. They are going to have Dual Core CPU's come out in the 3rd Quarter of 2005, as well as Intel. The advantage with AMD is that it will be compatible with existing hardware.

I *think* that Dual Core CPU's will be introduced on Socket 939 and definately on Socket 940. I have no idea about Socket 754.

Anyways, if you go AMD64 and Socket 939/940, by the end of 2005 you'll be able to buy Dual Core processors to essentially double the processing power of your computer. It won't have a large impact in games since those don't scale in performance with extra processors, but video processing and some other multi-threaded tasks will see large improvements. At these levels though, it would be pointless for a file-server because file-servers generally do quite well even if they are an old Pentium 3 500MHz system. It would make for one heck of a workstation, however.

Anyways, look at AMD. At some point in time I or someone else should figure out which platform's Dual Core will come to (939/940) and provide some recommended hardware. As far as everyone has been told by AMD, it will be possible to "drop in" Dual Core processors into current motherboards. Intel can't do the "drop in" and would need you to upgrade motherboards also. Food for thought. Cheers.