Unused transceiver TX channels in your Arria® 10 device may degrade over time when using the Quartus® Prime software version 16.0 and earlier.
The Quartus Prime software generates a warning message if your design contains unused transceiver channels. The warning message states that performance of unused channels may degrade over time if not properly preserved with the following Quartus Settings File (QSF) assignments.
Global Assignment
set_global_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON
Pin Specific Assignment
set_instance_assignment -name PRESERVE_UNUSED_XCVR_CHANNEL ON -to pin_name
In the Quartus Prime software version 16.0 and earlier, the QSF assignment only preserved the unused receiver channel and did not properly preserve the unused transmitter channel.
To preserve the performance of unused transmitter and receiver channels in Arria 10 devices you should recompile your design in Quartus Prime software version 16.0.1 or later.