Arria10 DDR4 controller

Hi, I want to ask some questions about DDR4 controller in Arria10Gx1150 device.

According to arria10 spec, ddr4 controller can support maximum 144 bits widths. If i want to design 128bit widths in ddr4 application, the ddr4 data rate can achieve 2400Mbps? Or it is better to use two 64bit ddr controllers to decrease skew and delay? Because two ddr4 controllers are commonly seen in most application. I hope to get some support datasheet and if you have verified 144bits widths are ok, thanks.