FletchDonJuan

Thanks to everyone for the input and feedback, this is super helpful. Out of curiosity, how difficult is it to tweak this stuff in the BiOS? Is it as simple as inputting the lowest specs of both sticks?
 
Also, once I boot into Windows how do I check to make sure both sticks are working properly? Task Manager>Performance>Memory?

Update: everything worked just fine and I validated in CPU-Z that both sticks are working in dual channel. Thanks everyone for the help!

Ive mixed brands and specs throughout the different specs. Some refuse to work. Most will work if you manually set timings and such to match the lowest performing set. Usually i found that if you mix on the two channels you dont have a high chance for success but if you mix 2 together per channel, setting it this way usually works. So say, 2 corsair in A1, B1 and 2 Kingston in A2, B2. Wife is running a mismatched set and until i manually set timings (frequency was the same) it was very unstable. Now you wouldnt know they were mismatched.

It should run but it will revert to lowest speed, and highest latencies between both sticks, sort of the worst of both sticks.  If you are going from single to duel channel memory though this should more then offset any performance penalties from that as single channel is very sluggish/stuttery.  Make sure to install sticks in either even or odd slots, 2 and 4 (usually prefered slots on most motherboards) or 1 and 3 so that memory runs in duel channel.

 

It seems ok, but you will either have to overclock your GeIL Evo Potenza to DDR4-2666MHz, or downclock your DDR4-2666MHz Apacer ram to DDR4-2400MHz. Also you will need to match the timings and CAS latency's in the BIOS settings.

it might mix, if it does though you will have the 2400mhz clock speed because thats the highest both sticks can achieve, as with the cas that might be a problem and cause incompatibility but im not 100% sure