I have 2 x 4GB Sticks and 1 x 8 GB stick and experienced framerate downgrade.

ImCODEX

Commendable
Oct 8, 2016
4
0
1,510
So I am running an 1 x 8GB stick in the first slot and in the 2-4 2 x 4 GB ones. First I tried with the 8gb stick in first slot and 1 4gb stick in the 3rd and one in the 4th and it didn't boot. So the question is: Can I somehow arrange the ram so programs acces first the dual channel kit and then the single one?
 
Do you need more than 8 GB's? What is your current usage? I would either run the kit alone in the correct slots for dual channel or else sell what you have now and pick up a 16 GB kit. You sound like you are running into problems running in dual channel mode and perhaps with timings and frequency.
 

ImCODEX

Commendable
Oct 8, 2016
4
0
1,510
When I was running only 8 gigs the usage was around 80-90% all time when gaming, I have the same brand, timings and frequency, only difference that 1 stick is 8gb's. I am also planning on buying another 8gb stick so I can have 24 in total.
 
Mismatching RAM, even if it is the same model, isn't guaranteed to work correctly. This is the reason they sell kits. And if you are only running 80 to 90 percent usage, adding additional RAM isn't going to make any difference, the PC will only use what it needs. Since you've already seen that the FPS has fallen off when adding more RAM, I would go back to the 8 GB kit and upgrade to a 16 GB kit when your usage goes over 90 percent.
 

ImCODEX

Commendable
Oct 8, 2016
4
0
1,510
Yes, but in games like Call Of Duty Black Ops 3 I barely can run it at low settings with only 8 gb's of ram, with 16 gb instead I can run it at high. That's why I need 16 gb ram. Can I somehow run 1 x 8gb and 1 x 4 gb stick in dual channel?