what you don't realize is that Intel (and AMD) have built their business
on makeing sure that their new CPU's run existing software with no
modifications, (and almost always faster then the old versions). remember
that for most of the world, getting the software modified would mean
buying a new version, if the vendor bothered to make a different version
for the new chip.
if they required everyone to buy new software to use a new chip it
wouldn't work well. In fact Intel tried to do exactly withat with the
itanium and it has been a spectacular failure (or t the very least, not a
in theory they could change anything at any time, in practice if they
break old software they won't sell the chips, so the modifications tend to
be along the lines of this one, adding detail to the specifications so
that programmers can get more performance.