Where are the old ppsspp dev builds

[LunaMoo]

You see you already did run a simple test proposed by Bigpet in which you added completely useless/wastefull load on cpu which wasn't synchronized with any actual job and did show up with MT on.
This proves that MT works fine, if it doesn't look like it with normal usage, it's because your OS knows better that it doesn't have to and that means a bottleneck somewhere else does exist. While we like to simplify it to gpu/cpu pair, it could be anything from memory, storage, mobo, display refresh rate or even caused by some programs running in the background, generally mobiles are somewhat short term devices and have more marketing than actual power in themselves, to cut price some important components that aren't used in advertisement are commonly really bad.
No clue how to check all of that on android:|. I would start by disabling any applications including widgets, animated wallpapers, custom keyboards or any other stuff that's not the base of the OS. Trying different storage for iso, or even using frameskip(android apps always uses vsync, so basically your fps will never get above display refresh rate and that can actually be low and weird on some devices;p).

You might still think it's PPSSPP problem with your device, but it's rather your device problem with heavy applications. PPSSPP could get some hack or something, it's not like it already doesn't have such things. The thing is, it's just your issue, and nobody knows what's the actual problem if there really is and if there could even be any workaround for it. You're dedicated to prove it's a threading issue, while the test you did earlier on github proved clearly it's not that and you going into it makes you at best an irritating fellow who picks only the things that could prove his own theories from other people's answers. Seriously nobody, and I do mean NOBODY likes that. Nobody here is your enemy or treat you as Nazi Zombie, but ultimately you'll always hear an answer to fix it yourself if you keep repeating to be the only one to understand the problem.

Your tests are also don't have much worth in them, you might as well run one buggy or heavy game as far as we know. Even with MT you can put different things on threads, but cannot divide some others, it's not an universal tool to share load, if the game you test would use mostly one heavy thread it couldn't be divided on 2 cores, your test would be completely worthless, just a waste of especially your own - time.
Look how Solarmystic tests stuff, if you look at some github issues, you'll often see him doing tests on pc. Taking huge variety of differently working games and makes notes of different things not being blinded by the expected stuff. That's how testing should look like, not showing a screenshot of some cpu load tool running who knows what apps in the background and no legend/description included other than "this is my proof":]. As far as I would see this screenshot myself it shows a load of 2 cores, both being busy one mostly by some "applypatch" which I assume by google is your android updating something during your test the other by some "thread-969" which I assume by pure guess is ppsspp. Nothing usefull shows there at best by guessing it says that one your cores is eated by some process, the second one by some other one.