helpmate brothers

my plant is 6GB of RAM. 4+2GB settings = DDR3L, 1600MHZ,PC12800, timing of 11.13 a voltage of 1.35.
chose to replace two of the same Board 4+4GB settings = DDR3L, 1866MHZ, РС14900, timing 10,10,10,30. a voltage of 1.35.
as shown by the quest to find a more or less normal DDR3 is still necessary to try.
replacement worth it?
and in General, if this choice under my system settings? (it will support my motherboard 1866MHz?) (choose the RAM the first time)

processor = Intel® Core™ i7 4700HQ Processor
video = Integrated Intel® HD Graphics 4600 *1
NVIDIA® GeForce® GT 840M with 2GB DDR3
motherboard = Asus X750JN
memory = DDR3 1600 MHz SDRAM, 2 x DIMM socket for expansion up to 16 GB SDRAM
chipset = Intel® hm86 chipsets Express Chipset
win 10, 64