Question 4 ram in dual channel

[Stelios_2]

I want to build a system for editing and rendering, the motherboard supports only dual channel
I see any difference in bandwidth if I buy now one set 2x8 and later another set 2x8 instead I buy one set 2x16

The ram 2x8 https://m.newegg.com/global/gr-en/product/N82E16820232751
The ram 2x16 https://m.newegg.com/global/gr-en/product/N82E16820232752

 

[Gam3r01]

RAM is only guaranteed to work in the kits its sold in, so buying 2x8 now with plans to add more may not work, most of the time it does, but something to consider.
Ideally, you buy however much RAM you need now, not only do you not have to worry about it not working, but using only 2 sticks ever so slightly reduces demand on the memory controller compared to 4 sticks.