I am using After Effects with i3 8100 and gtx 1050. But GPU isn't usable for rendering and CPU very slow in heavy work. So i have two options, first relplace i3 8100 with Ryzen 7 3700x. The other is to replace 1050 with rtx 2060 super or gtx 1660 super. Which option will give me a better performance ?
AE barely uses GPU features at all, so there is no point in upgrading your grphics hardware. A GTX 1050 is still plenty and in the situations where it isn't used, AE won't use another graphics card, either. So under any conditions upgrade your CPU first.