Another fine asset from Yal! I just wanted to let you know I am also getting 15-20 FPS on the provided demo level in the GM:S 1.4 version. The GM:S 2 version ran around 25-30 FPS. I have a GTX 1070 gpu and a great processor so my rig shouldn't be an issue. Probably just the limitations of Game Maker in 3d I would assume. Keep up the amazing work!
Interesting... I'm on a GTX 1060 / i5-8300 rig these days so I would've expected your performance to be better than mine. (Bigger numbers means better hardware, right...?)
At least the "GMS2 has better performance than GMS1" result is congruent with my testing - it's not as noticeable when both run relatively stable 60fps but the difference is gigantic - something like 500 fps_real for GMS1 vs 800 fps_real for GMS2.