Fast 1/X division (reciprocal)

Question

Is there some way to improve reciprocal (division 1 over X) with respect to speed, if the precision is not crucial?

So, I need to calculate 1/X. Is there so

Answer 1

The fastest way that I know of is to use SIMD operations. http://msdn.microsoft.com/en-us/library/796k1tty(v=vs.90).aspx