Right now I have a 4GB RAM stick DDR3 1600MHZ Crucial ( full product name: 4GB DDR3 1600 MT/S PC3-12800 CL11 Udimm 240-Pin Single Ranked ). I'm planning to get 8 more GB RAM though I'm not sure if I should get 2 x 4 GB RAM sticks ( same model as the one that I have) or a single 8 GB RAM stick ( same model but with different part number ( I don't know if part number matters ) ).
What should I get? My mobo is a GA-970A-D3 that supports 32 GB RAM. I'm guessing that I should get the 8 GB stick, in case I'll plan to make future upgrades but I'm asking for what should I get for now, for the upcoming games like Assassin's Creed Unity or GTA 5 etc.
It is always recommended to have the same model/size/speed ram installed, this is to avoid some system stability issues that aften arise when mixing ram. If you do get the 8 GB stick i would recommend that you remove the other 4GB stick.
Howver ther is nothing wrong with 16 GB (more than sufficient)in a gaming rig so filling you machine up with 4's wort hurt you performance
yes, it'll probably work in single channel, or it might work the first 4+4 GB in dual and the remaining 4 in single. getting another 8 would be better.
real world maybe 5% overall performance difference, memory is very fast anyway, there is bound to be a worse bottleneck somewhere else.