Multi-CPU utilization for combinator attack on a modern GPU

[epixoip]

Hmm doesn't quite sound like you have a grasp on the issue. Are you talking about when piping combinator.bin from hashcat-utils into oclHashcat via stdin? If so, the issue isn't that it can't generate candidates fast enough on the CPU (or at least that's not the biggest issue.) The issues are 1. you have no amplifier (this is where GPU acceleration comes from with fast hashes) and 2. host-device transfer latency. You could have a dozen CPUs generating candidates, you still won't get any GPU acceleration that way.

But we have a native combinator attack mode in oclHashcat so piping combinator.bin into oclHashcat is a bit stupid anyway. What precisely are you trying to accomplish?