Re: Is 70ms 14 or 12% faster than 80ms ?

[Albert Chan <albertmcchan@...>]

>> Is 70ms 14 or 12% faster than 80ms ?
>> 
>> Reading many stackoverflow response, I am still confused.
>> Most answers claimed (1 - 70/80), or 12.5% faster
>> 
>> --Albert
> 
> it takes 12.5% less time
> that makes it 14.28...% faster (1 / (1-0.125))
> 
> -- 
> Oliver

Thanks.  Stack-overflow is wrong !

-- %faster should be relative to speed

speed = 1/70= (100% + %faster)(1/80)
%faster = 80/70 - 100% = 14.3%

-- %slower should also be relative to speed
-- Example: 70ms job now take 80ms

speed = 1/80 = (100% - %slower)(1/70)
%slower = 100% - 70/80 = 12.5%

--> %slower will NEVER reach 100%