From Mark Middleton:
We are putting the Micron MT41K128M16JT part on the SABRE Smart Device board and the Micron MT41K256M16JT part on the SABRE AI board.
We were basically forced to do that because Micron went EOL on their 1.5V part.
The interesting news is that, while we are still using 1.5V rails for the new part, the customer can easily change the voltage rail to 1.35V at boot time, before the DDR3 is loaded, and then give it a test try. Might have to tweak on some register settings a bit to make sure everything is okay, but should not be a huge effort. Officially, we are not going to test that all out. Not enough resources.
Samsung devices: They should work, but we have not tested any. K4B2G1646E is the equivalent part to MT41K128M16JT