Are you having trouble with temps? I would highly recommend a tear down, cleaning and apply new thermal paste. I own the 7559 as well with the i7 6700hq. The CPU would peak at 98c while gaming without the gpu being overclocked. I applied new paste and cleaned out any dust and now I am down to 75c on the CPU and low 70s with +135mhz OC on the gpu core and 500mhz on the memory clock.
I try to play most games at 1440p at 30fps since i have the 4k touch variant of the 7559.
If you need help with disassembly i can do a guide for you. The few on youtube are crap.