[petsc-users] MPI speedup

[Jed Brown]

Matthew Knepley <knepley at gmail.com> writes:
> I don't like counting FMA since its a special, not a generic, floating
> point instruction, but
> I guess everyone does it.

It's not an FMA, it's issuing an independent add and multiply each
cycle.  Haswell has dual-issue FMA (so "16 flops/cycle").
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