when bound indicate days

for heated number-crunching i'm deliberation controlling bound indicate instead floating point. impetus it'll matter bytes bound indicate form size, cpu it'll controlling on, i (for intel) mmx sse whatever new things up...

i'm wondering days floating indicate runs faster ever, ever value deliberation bound point? there whole manners float where contend it'll matter some-more few percent? overview 35,000 feet numerical performance? (btw, i'm presumption whole cpu found many computers, dsp specialized embedded systems.)