laptop gtx 1050ti 4gb vs 1060 6gb

What's more, the GTX 970 was really only a 3.5GB card: Due to the way the memory system was partitioned, only the first 3.5GB operated at 224 bits while the last 512MB operated at only 32 bits. None of the memory on that GTX 970 operated at the full 256-bit bandwidth.

All 4GB of the RAM on the GTX 1050 Ti operates at its full 128-bit bandwidth. But because you're using a lot of Lumetri effects, some of which are GPU accelerated, you may run out of RAM on the GTX 1050 Ti almost as quickly as you did on your old GTX 970. And when you run out of GPU RAM in the middle of the rendering of a given clip, the MPE renderer will lock itself into the software-only (no GPU acceleration) mode for the remainder of the render job for that clip.