slow down when using scaling

[LunaMoo]

Then maybe the effect which this game uses is simply weirdly heavy and with upscalling your hardware cannot handle it. Yeah I saw what you have, it's not exactly a weak hardware and in fact it's normally way more than enough for ppsspp, but that doesn't really matter in emulation. The thing is that some games do certain effects in a very weird ways that pc hardware was never optimized for, and this will not be the first game with such problem.

If you really must upscale textures I would recommend to check "disable slower effects"(in graphics settings of the new 0.9.9+) and see how the game works with it as some games do alot of work with no noticeable result and you can turn some of it off fairy safely.
If it doesn't help, or disabling those heavier effects actually glitches the game, try using auto frameskip set to skip 1 or 2 frames at max. The game will still be smooth normally, and drops few frames only when it needs to, hopefully keeping the full speed with a nice sound.