I have been able to tweak MJ-12 from 5 up to 12 workers and remain fairly stable. I turned it up to 17 workers Sunday night and my system shut down Monday some time. When I came home from work my system had started to reboot and was stopped at the password box - so no crawling or crunching for several hours at least. So I tried reducing MJ-12 to 15 workers and while my system was stable yesterday evening I couldn't get online without shutting down MJ-12. So 12 workers seems to be the sweet spot for my system.

At 12 workers I can get from 200,000 to 240,000 credits a day. It's not enough to hold off the other teams, but it seems to be all I can do.