Guide:- Maximizing the performance of PPSSPP on your Android/Windows device.

[mr.chya]

what you want to change is window size not rendering resolution. here's what the performance guide says about rendering resolution:

7. Play at only 1x or 2x rendering resolution.

(Note:- Applies to both Android and Windows now since v0.9.1-752-g2745744 which seperated Window Size and Rendering Resolution.)

(Note 2:- Changing the rendering resolution will only work if Rendering Mode is set to Buffered Rendering. Non Buffered Rendering Mode will just lead to the image being displayed in your device's/window's native resolution. E.g. If your device can output 1080p, and you set it to Non-Buffered Rendering, the game will render in 1080p no matter the rendering resolution set in the options. You'll have to set it back to Buffered Rendering, and then, change the Rendering Resolution to whatever you desire.)

(TL: DR, Choose either a low rendering resolution (1xPSP or 2xPSP) coupled with Buffered Rendering Mode OR just Non-Buffered Rendering mode, and compare the performance for yourself. You can't have both Non-Buffered Rendering Mode AND the choice of your rendering resolution at the moment.)