I tried emulating an NES game with nes.emu and had an insane amount of input lag from my Matricom gPad that made the game unplayable. The gPad is wireless over BT. Anyone else have issues with this?
Also, I tried using RetroArch for emulation to see if the input lag was there but it kept auto configuring the gPad and only about 1/4 of there buttons were functional so I couldn't navigate the UI.
I experienced the same thing and looked at settings in the retropie, nothing worked. Then someone mentioned if your tv has a movie and game mode, switch it to game as movie mode refreshes the screen more. Worked fine after that, hope that helps!