Here are the results so far:
Optimizing the animation system: 0,7 fps ---> 1,2 fps
Better shadow code + eliminating SQRTF-s: 1,2 fps ---> 1,4 fps
Optimizing the 3D renderer for weak FPU: 1,4 fps ---> 1,6 fps
CPU: Cyrix 6x86MX 200 MHz

The optimizations will be continued later, as currently i dont have more ideas how to optimize it further.

I will test the engine with Intel Pentium MMX (200 mhz), Intel Pentium (90 mhz), Cyrix 6x86L (150 mhz), and AMD K5 (90 mhz), VIA C3 (533 mhz), Vortex86DX (800 mhz) CPU-s soon, just for comparison, and i will post the graph here.

(On Pentium 4, AMD Athlon XP, and Pentium3, i already know that the engine is fast enough so no point testing on those).