upgrade from amd 2600 to AM 64

[tesco]

The default fsb is 1600mhz i think.

the default one is integrated onto the chip. As is the multiplier and vcore(voltage of the chip). but you can change the vcore and fsb in the bios if you want.
Im not certain about the 64bit chips, but on most chips the multiplier is locked.

[lynx]

Go for this instead:

http://www.newegg.com/app/ViewProduc...103-502&depa=0

You also get the HSF, you don't get that with the OEM product.
Warranty is much better on the retail product too.

The memory controller is built in to the Athlon 64 chips, the 939 pin version has dual channel capability, 754 pin only single channel. Remember that is right to the chip, something the old dual channel Socket A motherboards couldn't do with their external memory controllers, so it really works. That is one of the big advantages of these chips compared to Socket A chips, even if you don't fully exploit the 64 bit capability.

Socket 939 also have 25% faster hyperchannel speeds, 1GHz compared to 800MHz for socket 754.

[clocker]

Go socket 939...I believe that is the platform that AMD will expand/support for a goodly while, but don't get it yet.
Find the new chips which are based in the 90nm process (smaller=faster).

The new gen of nForce4 boards will be available soon ( right now Asus is the only choice) and the combination should be great, but kiss your high end AGP vid card goodbye and go PCI express (you have no choice really).

There ARE 64-bit OSs out already...MS has a free beta XP64 edition and Mandrake Linux is 64bit also.
Appropriate drivers are becoming readily available to suit.

[Shiranai_Baka]

Any information on the cores? I googled a bit but found it confusing and it didn't really explain on the cores.