My personal testing has shown DSP LLE On Thread to be a net loss for performance. It seems like most (if not all) people experience this. Someone in #dolphin-emu or #dolphin-dev mentioned that they first started noticing it after the migration to Visual Studio 2013, which is the best reference point that I have at the moment.
If it's not providing a benefit, just disable it.
*EDIT: Take this with a huge grain of salt. It's entirely possible that something else "broke" DSP LLE On Thread's performance gain.
If it's not providing a benefit, just disable it.
*EDIT: Take this with a huge grain of salt. It's entirely possible that something else "broke" DSP LLE On Thread's performance gain.