Throttling GPU and CPU

First of all sorry for my English. But I really don't know what to do! After ~ 10 min gaming i get huge frameskips and framerate drops! I have observed that my hardware gets the throttle.

I've reset SMC and PRAM countless times and there's no difference.

Does anybody know how to fix this problem? I founded "ThrottleStop" software to fix CPU throttle. But for gaming I need to use perfomance graphic!

Temperature when frequency is lowing down about 60-65C. It is not so hot to make "safe option"!

Specs:

MacBookPro with Retina Display (Early 2013)

Nvidia GT650m 1GB

Windows 8.1x64

P.S on MacOs I didn't do any benchmark tests but i'm pretty sure that i have the same problem, 'cause a game begin to get lags (not so huge) after 15-20 minutes.