There are a LOT of A7V models. There is the original A7V (and various versions of it A7V-M for example), A7V133, A7V266, A7V333, and A7V8X.
The original A7V uses the Via KT133 chipset, which can only accept 200 MHz FSB Athlons. That means the fastest CPU it could officially take (with a bios update) is a 1400MHz 200 MHz fsb Thunderbird. That would be extremely hard to find, as they were rare to begin with. Most of the 1400s were 266 MHz FSB parts. They made 700, 750, 800, 850, 900, 950, 1000, 1100, 1200, 1300, and 1400 MHz 200 MHz FSB Thunderbird Athlons. You could use any of those, or a Duron at 950 MHz or below. (With a special beta bios you might be able to use up to a 1300 Duron.)
If you have the A7V133, you can use any Athlon up to the 2100+ Athlon XP with a bios update.
The A7V266 could use up to a 2600+. The A7V333 and A7V8X can use all the way to the 3000+ being released Monday.
