The Athlon 64 is the Athlon XP replacement. This processor can outperform the Athlon XP even at equal clockspeeds, thanks to the many improvements of the K8 technology set. Since I already covered what makes this processor different in the technology overview, I won’t repeat myself.

There are two Athlon 64’s available, the basic Athlon 64 and the Athlon 64 FX. The FX series are supposed to be the most high performing processors you can get, and as a result come with a price tag to match that high performance. A special feature with these processors is that their multipliers are unlocked, meaning these are the best choice for overclockers (if you can afford it).

Beware though. The thing that makes a processor part of the FX series is that it is the most high performing processor at the time. Usually this means it is 200MHz faster than the fastest Athlon 64. So what happens is when AMD release a faster Athlon 64, it is released under the FX name, and then a regular Athlon 64 is made that runs at the same speed as the old FX. For example, lets take a look at the price of the 4000+ and the FX-53:

4000+: http://www.newegg.com/app/ViewProductDesc.asp?description=19-103-497&depa=1

FX-53: http://www.newegg.com/app/ViewProductDesc.asp?description=19-103-459&depa=1

Yep, you are reading that right, the processors are identical apart from the unlocked multiplier the FX processor has. But look at the prices, the FX processor is $727 while the 4000+ is $649. So what happens is the old FX processor is still available to buy, but there is also a regular, identical cheaper Athlon 64 available. Just be careful.