Diffrent sizes of RAM

[Niewierzyc]

I have 8gb and 4gb 1600 ram sticks in dual channel, they are same speed and same voltage just they are different sizes, is it okay?

 

[brispuss]

If Flex Memory (or equivalent) is available, and if other DIMM parameters are similar also, then the two DIMM's may operate partly in dual channel mode, and partly single channel. 4 GB of the 8 GB DIMM will run in dual channel with the 4 GB DIMM, and the remaining 4 GB of the 8 GB DIMM will operate in single channel mode.