I recently just bought all new parts for my pc including a nice new case, phantom gaming 4 z390 motherboard, 2 sticks of 8gb ram, h100i pro water cooler, intel i5 9600k processor, and a gtx 1660 ti. The only things i kept was my HDD that had my windows 10 and some games on it and my 900w power supply. For the first day it worked fine but i had my old graphics card which was a AMD Radeon 7950 sapphire dual-x and saw one fan wasn’t spinning. I turned off my computer and unplugged it and plugged it back in. When I turned it on everything went downhill and started to run way slower and when i moved my mouse it would lag. Now i have both graphics cards in my pc and it is still running slow. I installed all drivers and all that please help!