My R3 had a single slot I could add a 4GB ram to the on board 4GB. Your SP111 is the next generation but do not know if the same, guess you would need to remove the back cover to see if you have an empty slot. I show a 4GB DDR3L 1600 SO-DIMM 1.35V as the memory used but if already have a stick may need to replace with an 8GB. In any event I believe the architecture will only support 8GB max.
Sorry, do not have a SP111 so guessing at some of this.
ps be aware that on mine there is a microswitch under one of the center screws on the back and it will not turn on unless the screw is tight.
