Hi Onera it is not a good idea to mix ram from different manufacturers or different speeds , all same brand and all 1600mz or all 1866 or you will have no end of problems getting your ram to work if your system even boots up. get more geil same ram modules or more adata same ram modules
No... Just get rid of the 4GB ADATA RAM and use the 8GB EVO VELOCE RAM. Very few things even benefit from 12GB of RAM, and it's certainly not worth the problems associated with using mismatched RAM.
get the 8GB set, then you know you have 8GB that will work, if you can get the older stick to play so much the better (if you need help trying, give me a shout), if it won't play can sell it off or put in another rig