[ccache] ccache cache in RAM -- bypassing file cache?

[Martin Pool]

I think Justin is right that there should be no copying; it would be
fairly insane if there was.

I would speculate that the cause is nothing to do with the cache, but
rather just that on the larger machine, more of the source tree and
the header files used by it can be kept in memory.

You could try with tmpfs instead to see if it's different.
Martin