Github user rvesse commented on the issue:
https://github.com/apache/jena/pull/297
I think leaving at 2 is good, I was playing with using
`<perCoreThreadCount>false</perCoreThreadCount>` though obviously that lessens
the benefit. I think we can close this out though if we've delivered
noticeable improvements already, not really worth tweaking the configs too much
as any further gain is likely limited---
