[Help Needed] Hackintosh is stable, but at times laggy.

Hey guys, my Hackintosh is pretty stable, never had a panic, but and benchmark results are fine for both graphics and CPU. However, at times it is very laggy,$

Specs

iMac (Retina 5K, 27-inch, Late 2015)

Processor 2.71GHz Intel Core i5

16GB RAM

500GB SSD

GTX 1060 3GB

OS Version 10.12.6

4k display (same performance issue with 1080p)