https://www.wo-we.com/collections/mini-pc/products/mini-pc-amd-excavator-a9-9400
I am guessing that this is the mini PC you are referring to and so then I would avoid it, it won't be able to do PS2 emulation very well at all.
Launchbox doesn't run the games and has no impact on how well a game runs or doesn't run, the systems hardware determines that. I would also strong recommend against running emulation at 80%, it would be a terrible experience but that is just my opinion.
If you wanna run PS2 and possibly PS3 emulation it's hard to give you an exact recommendation but I would start with a lower end Ryzen CPU and some sort of actual graphics card like a 10 series Nvidia, like a 1060 or 1070 minimum. That would run PS2 very well and maybe PS3 but because PS3 emulation is still in its early stages speed is very hit and miss depending on the game and emulator development stage.