It may be possible to improve the range of RD (CR105, CR110) using the 0x505 setting on board Rev H:
I would recommend changing PHY_RDLAT (DDRMC_CR126 bits [13:8]) = 0x9.
This should give the Read Burst one extra cycle to complete. This is important because using RDLAT_ADJ = 5 starts the Read timing for the pads one cycle earlier.
