[YLUG] Why is this so much faster on an Opteron?

[john halewood]

On 24/09/2007, Gavin Atkinson <gavin.atkinson at ury.york.ac.uk> wrote:
> P4 CPUs are notoriously bad at handling infinities, as well as NaNs and
> denormals.  Usually this isn't a huge problem, but on the first
> iteration, i == j == 0, so the division becomes "0.505/(0/1)", i.e
> infinity.  P4 CPUs are notoriously bad at handling infinities, as well
> as NaNs and denormals.  Once f == infinity, all your future divisions
> are also affected.

Can I claim the speed record for this? On my Alpha (EV56, 600MHz), I get:
time a.out
Floating point exception

real    0m0.008s
user    0m0.002s
sys     0m0.005s

There's obviously some benefit in old technology.

cheers
john