Hmmm... well, if you think about it in overclocking terms, maybe the 900 athlon. Think about this for a minute

Most durons can get to 900-1000 pretty easily, and the lower clock speed athlons can usually overclock to 900-1000. Sooooo the 900, in a way, could be considered the slowest (in overclocking terms) AMD CPU. If that doesnt make any sense to you guys, i'm sorry...hehe
