So my specs are:
GPU: RX 480 NITRO+ 8GB
CPU: Ryzen 3 1200
RAM: 8 GB DDR4
HDD1: 250 GB (PC HDD, Local Disk C)
HDD2: 1 TB (Laptop HDD, Local Disk E)
So in many games it's looking like I'm having some bad performance. In minecraft frames drops, In League Of Legends the frames from 120+ decrease to 50 fps in teamfights, GTA V Online, only 30 fps on lowest graphics, v-sync off.
No idea what resolutions you are trying to play at so you might try reducing that to get some extra frames.
An RX 480 is starting to show it's age and it looks like by comparison your other parts are a bit slower than that.
Unless you used to get better frames and say, after a driver update it got worse? Then my best guess is you should likely start looking into getting faster components to help.
The fact that when a lot more going on in LOL for instance you get frame drops can be both CPU and GPU performance. Use the performance metrics and see what kind of load the CPU and GPU are under when this happens.
GTAV really likes more than 8gb of ram and suffers with 8gb.
AMD has a nice FAQ about the performance options: https://www.amd.com/en/support/kb/faq/dh2-020
You best results though are likely in game settings. Changing the quality settings to a lower preset may help. Turning off anti-aliasing and ambient occlusion in game can help a lot.