AE doesn´t recognize my RX 580 8 Mb VRAM GPU, but PS does

@pat pro also! if it's a laptop, both the IGPU and APU should have access to normal RAM, giving a viariable VRAM!

Yes, that's right! My 3090 makes nearly no difference from my old 2070. 

AMD is currently working on drivers to sunset older cards and add new general features. try a couple versions behind or checking for patches. if you're on windows, definitely check for updates, and restart. AMD doesn't have the same level of self-install to its drivers as nvidia. you'll probably need to go to the GPU manufacturer's site to get the cutting edge AMD drivers. perhaps you even have a driver or firmware meant for a different AIO's 580. if MSI and powercolor both have one, then their drivers and firmwares will have different defaults.

buuuut I wouldn't worry about that. GPU's make nearly no difference in after effects, and massively increase the chance of bugs and errors. I stopped using mine for renders and it actually sped up. 

I hope for you that it has 8GB of VRAM?