Noting this down so I don’t forget …

hdparm buffered read test: 48 megs/second.

Writing small files (from Python): 100,000 1400-byte files (133 megs) in 24 seconds. i.e. 4000 1K files per second. — 5.5 megs/sec, but all over the place.

Writing huge files (from Python): 1Gb in 35 seconds. — 28 megs/sec.