Thread Pools - Single vs Per Machine

RandoCalrisian

In what case would I use a Thread Pool set to Single vs Per Machine?

The HelpFile of the Thread Pool object says Per Machine would be used for Render, but it doesn’t specify under what circumstances Single should be used.  To that end, why couldn’t I use Single for Render?

In what scenarios would I have multiple Thread Pools set to Single?

GrooperGuru

You can't use single for Render due to the mechanics of the Black Ice Driver. It stores the PDFs it creates temporarily in a pre-defined directory that is the same regardless of which user on the machine is performing the rendering work.  Grooper then expects a PDF to exist in that location with a specific name. If you set it to single, then you could theoretically create a second thread pool in single mode and have both of them doing render work on the same machine, which would cause mass chaos and world devastation.

RandoCalrisian

Well there isn't any specific about the Singe setting that prevents its use for rendering, outside a bad setup causing said chaos, correct?
If you had just one thread pool set to single, it'd still work?

To that end, what specifically is a Single thread pool used for?  What does it allow that Per Machine does not?