I am currently playing SC on origin pc evo15s(2014 model) that has a gtx870m. It feels a bit choppy and laggy at times so I want an upgrade. Any suggestions to a desktop that can run SC very smoothly with a 144p?
Do you also have other hardware except for the notebook?
Otherwise, it depends on the budget.
In terms of price-performance you should aim for something like Intel i5 / R9 390 or GTX 970 / 8-16GB RAM or better.
Depends on your budget
Or just wait at least until Squad42 is flight ready.