Well. I got my Athalon 3200+ knowing it was a 2.2 Ghz processor, &
didn't know it was supposed to be equal to a 3.2 GHz P4.
I really do not think it is equal to said P4, and is doing it's thing
at a 2.2 GHz pace. Perhaps there is a certain kind of process it
excels at. I am quite happy with it, and got a good deal on it.
Big Mac
When AMD started their XP rating system, it was a more accurate
representation of CPU performance relative to a P4. Things changed
though, and the P4 got more cache, hyperthreading, higher FSB, so their
performance remained somewhat more linear to clockspeed increases while
with AMD they had started with a slower FSB so when they increased FSB and
cache, their XP numbering system seemed to rise disproportionately. In
other words, an XP3200 is not 3200/1800 as fast as an XP1800.
As for optimizations to get the projected performance, it's somewhat the
reverse of your theory. In hard number cruncing of unoptimized code, AMD
has the faster chip per XP rating, but it's when the most modern apps are
optimized for SSE2 than a P4 shows it's worth. If you're not running
newer software then the odds are in the Athlon's favor, but then so many
of the more common tasks aren't even CPU-bound, the median priced CPU
combined with higher-end video card or hard drive may be the best
combination for many people.
The XP numbering system is at least valid to the extent that your idea of
a 2.2GHz Athlon "doing things at a 2.2GHz pace", is meaningless, because
it is without question much faster on average than a 2.2GHz P4 except
"sometimes" at video editing apps optimized for SSE2. Some tasks benefit
more from one architecture than the other, but this has always been the
case.