Thank you!
Basically what C12Friedman said is correct, in that quad channel memory (4 modules) is the better choice here for the system to provide maximum memory bandwidth.
Although the A-Data memory is fine, some suggested alternative quad channel memory which should provide better performance than the A-Data memory are -
G.Skill DDR4 4 x 4 GB @ 2800 CAS 16
Mushkin DDR4 4 x 4 GB @ 2800 CAS 15
Kingston DDR4 4 x 4 GB @ 2800 CAS 14
However, for increased performance (reduced CAS), there is a price increase associated with this.
So, is performance more important, or is price more important? If performance is more important, then perhaps the Kingston memory is the best choice. But if price is more important, then the A-Data memory is the best choice.