The UE4 doesn’t run very well on laptops especially with GT GPUs e.g I get 50-60 fps with my gtx660 M
But you could try this:
-run your PC on the “high performance” power setting
-check if you really use the GT555M → e.g my laptop has a intel and a nivida graphic card-.I always have to choose the nivida (you can change that in the nvidia control pannel)
I thought it may use the intel one instead of the GPU, but couldn’t find the app that shows if this is the case (I have the Nvidia control panel but it doesn’t show per app whether it’s using the GPU or not)