performance cost of sample conversion

[Psychological Cleanup via Digitalmars-d-learn]

if I have a non-double buffer and temporarily convert to double 
then convert back, do I save many cycles rather than just using a 
double buffer? I know it will bea lot more memory, but I'm 
specifically talking about the cycles in converting to and from 
vs no conversion.

Using a double for everything gives the highest precision and 
makes things much easier but is that the way to go or does it 
costs quite a bit in performance?