--restore after hardware upgrade?
I've got a long jon running in my cracking rig (weeks). It's started on 3 GPUs. I've got a 4th GPU. If I quit the job, install the extra GPU and --restore the job: will it work? If so, on 3 or 4 GPUs? Or will things get screwed up? Thanks!
Depends on how the job was started I suppose but assuming no strange initial parameters then it should pick up the 4th GPU fine as it's a job specified to run on GPU.

In any case, the easiest thing to do is take a backup of your .session file and try it out.