Hi coilbook,
i tested your scene;
1200x800pxls path tracing 2000 smpx on Laptop 16Gb Gtx1070:
Render mode:
frame 1202 geometry voxel > 3.08 min
frame 1202 render time 2.39 min
frame 1203 geometry voxel > 1.19 min
frame 1203 render time > 2.37 min
Render Viewport:
frame 1202 geometry voxel > 3.36 min
frame 1202 render time > 3.24 min
I sent a pm for more details.
Regards
Paride