What is the difference? In the end result is the same.
Suppose I'm using AMobile and MB that supports high multipliers,
wouldn't it be the same to set it to 14x133 and 11x166 (let's ignore
that 36MHz difference)? What is the difference? Heat? Lifetime?
Performance? I don't understand...
Higher FSB & sync'd memory bus will be faster, by a few percent,
maybe 5% if you pushed the FSB past 166 per your example.
The CPU would only run hotter to the extent that with a higher
FSB rate, it could do slightly more processing in same amount of
time so it stays nearer full load (IF the application is that
demanding).
Lifetime shouldn't matter, but stability can. Your motherboard
chipset must be stable at the chosen FSB speed, and likewise the
memory modules must be spec'd or overclocked to that speed, which
is a few $ additional cost but these days the price differential
is small.
With the mobile Athlon, you have to consider the multiplier if
you're not going to use software to change speed within windows.
Most motherboards can't support both <13X and > 12.5X
simultaneously, so you'd be limited to whichever range the CPU
defaulted to... some boards even default to 6X, and don't have
bios settings to change that multiplier so the cpu can't even run
at it's spec'd speed.
Ideally, if your motherboard and memory can handle it, your
target FSB speed should be closer to 210MHz, assuming you wanted
to o'c the CPU, otherwise you could save a bit of $ by buying the
on-mobile Barton. "Most" mobile bartons will run at
2.3GHz-2.6GHz, so taking the conservative estimate it might be
good to try 11.5 Multiplier and 200MHz FSB, @ 1.6-1.7 vcore.
YMMV.
