The tinderboxing was also coming over NFS from the same machine.
But I'd be astounded if the machine it was coming from had any problems
with disk I/O (similarly oversupplied with RAM and with half a gig of
cache on its RAID card: music does not need 250Mb/s of disk bandwidth!
Hell, at the quality I listen at, it doesn't need 250Mb/hr...)
And yes, it does seem that recording is the problem area, as so often when
the real world with its harsh latency bounds gets involved.