Thanks Robin, I think you missed what I mentioned in my first post.
This problem started with 10.1.4 auto-upgrade.
10.1.3 was super, Fyi, i just wrapped a 15 angle multi-cam edit for a four hour live show without a problem. FCPX media handling is fantastic on my 12GB ram Imac. Kudos to the apple people for that.
I do understand the process of tech evolution as well as perils of working on outdated hardware. Well, I am neither working on outdated hardware nor on an obsolete OS.
What you have proposed is a last resort. I was hoping to find an intelligent way to fix the problem.