I'm able to play most 5-10 year old games that aren't tied to DRMs at 30-60 fps on a Pi [2] (and certainly on Ampere) using box64 and an AMD GPU (or Nvidia on an Ampere system), haven't spent much time with FEX-emu though.
[1] https://www.jeffgeerling.com/blog/2025/system76-built-fastes...
[2] https://www.jeffgeerling.com/blog/2024/use-external-gpu-on-r...
Portal 2 was hitting over 100 FPS. Half-Life 2 and DOOM 2016 hovered around 60 FPS. Shadow of the Tomb Raider and Control mostly stayed above 30 FPS, while The Witcher 3 and God of War usually hung out in the low to mid 40s.
- https://interfacinglinux.com/2025/06/30/fex-emu-gaming-on-th...
Whether it's Raspberry Pi, Orange Pi, Banana Pi, or anything similar, by the time you buy the SBC and accessories, you're looking at around $100. The N100 or N150 are obvious choices if you're looking for a small, low power block of silicon to get something done.