How to disable Arria II GX OCT

Hi

I am using the DDR3 (Altmemphy). May i know how to turn off OCT?

In the .qsf file, i have commented out the all the related signal like below:

# set_instance_assignment -name OUTPUT_TERMINATION "SERIES 50 OHM WITH CALIBRATION" -to mem_dq[15]

However, when QII fit, the fitter shows output termination: Series 50 Ohm without calibration.

Thanks.