== test dcc: plane0 dcc=yes vs plane1 dcc=no, otherwise identical ==
  read_bw[dcc]=522.457947  read_bw[nodcc]=520.425049  ratio=1.003906250
  FIXED: factor is (1.0 + 1.0/256.0) = 1.00390625
harness rc=0 (1 == defect demonstrated at baseline)