What are you going to use it for? Programming? Games? Everything?
What OS are you going to use or are planning to use? Dual booting?
What''s your budget? A CPU and motherboard does not a whole computer make.
Plan to overclock?

So many questions.

Some things to consider:
-For a dual processor machine, you need a dual processor aware operating system (e.g. NT). Win95/98 will not recognize the second CPU. Win2000, built on the NT kernel, will.
-Yes, the AMD Athlon is a good, fast chip (especially in floating point computation, which is important for graphics), but you might want to wait until the next generation of chipsets becomes available (e.g. VIA Apollo KX133, which will support AGP4X, 200MHz FSB and 133MHz Memory bus). They should be out soon.
-Check the compatibility of your applications with any CPU you consider. Some high end workstation applications (e.g. Pro/E) are still partial to Alpha chips, although this is changing quickly.
-Don''t but all you money into CPU Mhz. There comes a point when the CPU isn''t the bottleneck in your system...

ZomeonE: The new 64-bit architecture from Intel is called the Itanium. If you really want 1 GHz though, the current P3 and Athlon chips will reach that point this year (Kryotech cooled systems already have...but nobody''s going to get those). Just remember that 64-bit means ZERO compatibility with any of your current applications.

64 bit doesn''t mean zero compatability, it just means lesser. 32 bit programs will still run on a 64 bit processor (Alpha is 64 bit is it not? I''ve seen normal 32 bit programs running on NT on an alpha).Can we not run 16 bit programs on current computers?. Besides, we''ll see a ton of programs being 64 bit optimized...course, the worst part is that we''ll have to depend on M$ to properly support it.

Phoe: 64-bit does mean ZERO compatibility, from an assembly programming point of view (since assembly language is the lowest form of human-machine interface, this provides an excellent method of analyzing architecture details from a programmer standpoint). True, we can run 16-bit applications on a 32-bit system, but why is that? It''s wholly due to the fact that Intel, since the inception of the 8086, has held backward compatibility as a primary design consideration. This means that code compiled to run on the first 8086 should run on the latest P3 (i.e. the assembly instructions have increased in number and functionality, but remain compatible in format and syntax). That having been said, the current core set of instructions of the P6 architecture is a complete mess. Intel has decided to sacrifice compatibilty for speed and future design purposes in the move from CISC to RISC based architecture (and don''t flame me on that! Intel has said that Itanium will be RISC. If it''s not then it''s not my fault! Let''s see if they come through...).

In addition, when it comes to running 32-bit code on the 64-bit Alpha (or, perhaps, 32-bit code on the Itanium), yes, it can be done. This is accomplished via emulators and firmware, hardly optimal solutions. Maybe it''s just me, but if I were to shell out the money for an ultra high end Alpha, I wouldn''t waste the power in that way. Imagine, that''s like running the Java Virtual Machine for every program you want to run. Why waste the money? By the fastest 32-bit machine you can instead, and use it to it''s full potential.

ZomeonE: Sure, 6 simultaneous instructions is cool, although I hope you agree that this does not directly translate into a machine that is 6 times faster. And sometimes it''s misleading. If I''m not mistaken, the P3 can perform 3 simultaneous instructions, but only one of which can be a complex (e.g. floating point) instruction (SIMD may have changed that, I''m not sure. Maybe it was the P2 that could only do one complex instruction...). The Athlon can do any 3 instructions at once.

I''m sure the Itanium will raise the performance bar, as will sledgehammer project, but for now, it''s P3 or Athlon for most home users.