For laptops with onboard RAM will increasing the RAM make it run as single channel memory and reduce performance?

For laptops with onboard RAM with an open SODIMM RAM slot, the memory will run in dual channel mode when the system uses up to double the amount of onboard RAM and in single channel mode for any application that crosses over that usage. For example, if the system has 8GB onboard RAM, 16GB would be double and would run in dual channel mode up to 16GB memory usage. The system will run in single channel mode if more than 16GB memory is being used. While not ideal, operating in single channel mode will still be best if your applications use more than double the amount of onboard RAM.