Yup, the only difference is that 200Mhz. In fact, they'll overclock to very similar levels anyway, so if you wanted to overclock there is virtually no difference anyhoo.
Opterons are for servers really, and there's no point even looking at them unless you already have a Socket 940 board (they use a different socket to the A64 chips, 940 pins instead of 939). Not really worth thinking about for you.
Some A64s have 1Mb Cache, but the extra cache doesn't benifit the A64 as much as some other chips. for example the 3200+ comes as either a 2Ghz 1Mb Cache chip, or a 2.2Ghz 512Kb cache chip - but the 2.2Ghz one is generally faster for most things, despite the extra cache.
[EDIT]
The A64 and the Opteron are really one and the same; the same basic Core - Just like Intels Xeon chips are the same basic core as the P4 chips - the only real differences are the Chipsets/motherboards which support them, which tend to be designed for stability rather than outright performance/overclockability (Servers which crash don't get sold)[/EDIT]
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"Sex without love is an empty experience...
But as empty experiences go, it's one of the best" - Woody Allen<P ID="edit"><FONT SIZE=-1><EM>Edited by ChipDeath on 11/16/04 08:39 AM.</EM></FONT></P>