[Solved]Why is OpenGL slower now?

[LunaMoo]

Quite the opposite, PPSSPP got a full rewrite of OGL backend which is now designed for vulkan-like multithreading that made it a few times faster(this includes AMD gpu's). There were also some minor optimizations added that made it even faster.

If you have time you could always check which exactly build started that slowdown for you, most likely it will be render manager aka MT ogl aka your ancient laptop is throttling due to overheat caused by higher cpu usage and you should start saving for new one if you didn't like five years ago as your laptop place is the museum or worse and you should have no expectations of anyone supporting it.;p

You can also forever continue to use older PPSSPP versions, nobody forces you to update and clearly your hardware is to old to benefit from any major improvements or even to easily handle psp emulation at it's current state, plus most exciting things incoming to ppsspp in the future might be limited to modern backends like Vulkan which your hardware will never support.