Windows built-in Cipher secure wipe

Question

How secure is the bulit-in Cipher utility that can wipe out unrecoverable data on old harddisk?

Answer 1

I can't find the official documentation from Microsoft stating it, but I remember seeing that it uses a three-pass method for wiping the data. On the first round it overwrites with 0's, then on the second with 1's, then the third pass with random bits. So, it's not bad.