PPSSPP much better on much worse phone (XPERIA NEO V vs XPERIA J)

[Majkes]

I am able to play Locoroco in 60fps on my almost three years old xperia neo v. It has one core cpu and ridiculously low ram. Recently I acquired new phone, xperia J, which has a single core processor, more ram, better graphics etc. But the game works terribly, even with the same settings (except for enabled multithreading). I've tried every combination of setting and the performance is still around 15-20fps with very laggy sound. WHy is that, why is so much better device giving me much worse results?