Thank you I will try cpu. Gtx 1050ti always crashes blender when trying branched path tracing, so used path tracing with gpu.
When rendering reflective surface (floor plane) at 1920 x 1080 cycles, path tracing it looks great. But most reflective details on floor disappear and go dull with same settings at 8000 x 4500 for printing. Using 250 samples. Have also tried 1000 samples and does not help. Can path tracing do large sizes? Anyone know why details are weak at hi res size?