Eeeah! Slot boards have been successfully tested!
The video below shows the DDR3 version speed test. The DDR4 version has about the same speed. The difference is in the maximum memory volume that you can install and in the cost of memory blades.
The second news is that all the disks have been converted to a silicon motion SM2264 chip and now there is no confusion about the maximum speed. All disks now support gen4!