PPSSPP - Samsung Galaxy S6 Edge+ progressive Slowness

[LunaMoo]

Well your screenshot is pointing to a potential problem, you see you don't have an "octa core" cpu, you have two quad cores, one is 2.1ghz, the other one is 1.5ghz or as you can see on the screenshot 1500mhz. Meaning for some reason your operating system doesn't want to switch to faster cpu when PPSSPP runs, that could be caused by reaching GPU or any other limitation which your app doesn't really show, but could also just be your system not seeing PPSSPP as a heavy app which would be a fail on the OS side and don't really think there's any way to counter that without forcing it with apps requiring root as brujo55 wrote.

Also no you can't "utilize all 8 cores" - that's impossible at the same time on little/big anyway, however you will not be able to fully use 4 cores either as it for the most part depends on the game and PSP games were not designed to run on anything more than a single core cpu and that part can't be divided, no amount of work will ever change that at least no work that could still be considered emulation.

"Multithreading" option get's rendering on separate thread. Thread does not = core, your OS controls that. It also does not mean a speedup, those threads still have to communicate with each other and whenever one has to wait for another it get's worse, results will differ between hardware and games so taking other people settings is extra bad with that option. Also it's rather buggy, so if you're using it all the time, definitely try disabling it, it's surely not an option to keep activated all the time for every game. Also some of the issue it causes could possibly corrupt memory, so would recommend restarting emulation and not using savestates made with it activated as those keep all kinds of bugs by design.