So I wrote up my own pwd gen which outputs new pwds to stdout and can be piped into John.
I run like this,
mkpwds | john --stdin --format=gpg-opencl ciyam.hash
... give some output like this...
Compilation log:
Warning: gpg kernel has register spilling. Lower performance is expected.
Loaded 1 password hash (OpenPGP / GnuPG Secret Key [OpenCL])
and after letting it do about 4 million pwds this way (drum roll) I get about 30,000 c/s reported.
This is on 1x 5830. Not that much more than a fast CPU I guess but then I do have 3 available. I just haven't played with running multiple instances yet. I have to turn mining off on 1 GPU to get that. Otherwise, while mining, it gets about <20,000 c/s. This is on a low end Athlon cpu typical for mining.
So at 30,000 c/s it should take roughly 8 minutes to do a salt pattern. Or 2.5 if I can get all 3 GPUs going and manage to split the pwd stream.
Interesting! Thanks for the update
I can imagine there's more benefit from the GPU when the whole password generation thing can be put inside the GPU as well...