ASROCK M8 Use Manual page 102

tRDWR
Configure between module read to write delay.
tRDWRDR
Configure between module read to write delay from different ranks.
tRDWRDD
Configure between module read to write delay from different DIMMs.
RTL (CHA)
Configure round trip latency for channel A.
RTL (CHB)
Configure round trip latency for channel B.
IO-L (CHA)
Configure IO latency for channel A.
IO-L (CHB)
Configure IO latency for channel B.
ODT WR (CHA)
Configure the memory on die termination resistors' WR for channel A.
ODT WR (CHB)
Configure the memory on die termination resistors' WR for channel B.
ODT NOM (CHA)
Use this to change ODT (CHA) Auto/Manual settings. The default is [Auto].
ODT NOM (CHB)
Use this to change ODT (CHB) Auto/Manual settings. The default is [Auto].
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