suppose (purely hypothetical) i bought a system with an Itanium2 processor and Windows XP 64 bit edition.
aside from the emulation crap, what current applications would i be able to run directly in IA64 ?
applications i most often use are : MS Office, Adope Photoshop, Nero Burning Rom, and of course Internet Explorer 
and what about Athlon 64, is it fully backward compatible or something ? does it work with regular 32 bit windows, and/or 32 bit applications ?
Well, I don’t much about the Itanium aka Itanics, but they are mostly aimed at the server markets, not at a desktop like you would use it for.
The Athlon64 is fully compatible with 32bit Windows/Applications, and can run them at least as fast as comparably priced Intel Pentium4 chips. This article http://www.tech-report.com/reviews/2003q3/athlon64/index.x?pg=1
gives a detailed overview of the Athlon64, and benchmarks it against a couple other chips. The fastest Athlon64- the Athlon64FX-51 easily matches the fastest Pentium4, the 3.2GHZ P4 Extreme Edition, while costing ~$200 less, in 32bit apps.
As for software, IIRC WindowsXP 64 bit is still in beta, and their isn’t much software for it that uses the full 64 bits. You can get 64 bit versions of Linux, of course.
Yeah, you don’t need emulation - all 64bit CPUs are 32bit compatible AFAIK. Buuuuut, it’s probably not worth it, really. I own an HP Visualize B1000 workstation that’s about 5 years old, and could run Linux in 64 bit mode on it if I wanted to, but I don’t. No reason to.
There just aren’t many benefits yet. If it’s compiled for it, a program could use longer data types, and of course there’s the ability to address more than 4 gigs of memory, but that’s about it. I don’t know anyone with more than 1 gig of RAM right now, and until 64 bit programming takes off, there’s no big draw.
My take on it is it’s like strapping a hydrogen fuel tank onto new cars. You can’t fill it up anywhere yet, but eventually you’ll be able to, and after that you might not be able to do without it. Eventually I’ll want one, but right now I can do without.
Not quite true. I worked on Merced (AKA Itanic 1) for a while until I could clearly see what a bomb it was. It does not natively run IA32 instructions, but rather translated them in hardware into microoperations run on the IA64 instruction set. For various reasons I am not at liberty to discuss it was not done well. A benchmark I saw gave Itanic 1 running IA32 instructions at about 100 MHz. I belive later versions use software emulation, which was done well by Alpha, to speed things up.
The Athlon, I believe, is a 64 bit implementation of the IA32 instruction set. No reason to think it won’t run 32 bit code fine - after all this was done by Sparc processors years ago.
Bottom line - Athlon is the way to go.
I do. The photographer that I took my family to the other day was using an Apple computer with dual 800MHz G4 processors and 1.5GByte RAM. Damn, that was a fast system.
The photos he made were with a KODAK professional camera (I don’t know which model) and puts out 15 Megapixels. The photos were something like 70Megabytes, and he’d double click on one and it’d open faster than my piddly little 2.5 Megapixel photos that I get out of my Olympus.
Impressive as all hell, let me tell you.
if i had money to burn right now i would neither spend it on processor ( i got XP2400 ) nor ram ( got 1 gig ) but on a faster hard drive ( i have 7200ATA133 ).
i would get that new WD 10KRPM SATA hard drive with 4.5 msec seek time its $293 for 74 gig version.
with access time ( seek + latancy ) of about half that of what current top desktop drives have, this should be some jump in performance if system and program files were on it.