SymmetricMultiProcessing
One symptom that has shown up on the Zope Lists from time to time is a scenario where Zope actually runs slower on an SMP system. If you are aware of the possible cause / fix, please share the wealth, below.
Might it be feasible to bind the Python Global Lock to one CPU, so that the other(s) will at least be free to continue processing general OS chores, and a locally hosted Database Backend (MySQL?, PostgreSQL?) that zSQL Queries are pointed at?