DDR4 is the fourth generation of RAM (Random Access Memory) technology for computers. It replaces DDR3 and offers increased speeds and larger capacities.
Specifically, DDR4 offers operating speeds ranging from 2133 MT/s up to 4800 MT/s, CAS Latency (CL) from CL 9 up to CL 22, while its capacity has been increased up to 16 GB per memory module.
For speed (MT/s) and capacity (GB), the higher we choose, the better. However, make sure our motherboard supports the speed & capacity. As for the CAS Latency (CL) the lower we choose, the better.
G.Skill Aegis operates at a speed of 2400MT/s, CL17 with 4GB of memory per module.