I left this comment (awaiting moderation). While I agree that GPGPUs are ideally suited for this type of thing, I think a lot of the difference you're seeing c

I left this comment (awaiting moderation). While I agree that GPGPUs are ideally suited for this type of thing, I think a lot of the difference you're seeing comes down to the amount of skill and effort put into the NTLM cracking functionality by the authors for their respective products. ighashgpu is a single-purpose tool, whereas C&A does many things. My impression is that C&A is mostly used with rainbow tables (supplied elsewhere), whereas the author of the GPU tool is set on being the best. Last time I looked into it, my impression was that a modern CPU could probably be made to run no slower than 5-10x that of a modern GPU at this type of task. Faint praise, I know :-) As OpenCL matures, I suspect we'll see code written which can be benchmarked on both. Exciting times!