for example what's better
8GB G.Skill RipjawsX DDR3-1866 DIMM CL9 Dual Kit
PC3-14900U
CL9
RAS to CAS Delay (tRCD): 11
Ras Precharge Time (tRP): 9
Row Active Time (tRAS): 27
or
8GB G.Skill RipjawsX DDR3-1600 DIMM CL7 Dual Kit
PC3-12800U
CL7
RAS to CAS Delay (tRCD): 8
Ras Precharge Time (tRP): 8
Row Active Time (tRAS): 24
or
8GB G.Skill Ares DDR3-1600 DIMM CL9 Dual Kit
PC3-16000U
CL9
RAS to CAS Delay (tRCD): 9
Ras Precharge Time (tRP): 9
Row Active Time (tRAS): 20
for i5 4570, in future i'd like to swap it with an OC CPU