15 Dec 2016, 08:11

@Scandy let's see where lag can come from, depending on the input method :

  • GPIO : the mechanics of sticks/buttons do not generate any lag. The clock scanning the gpio + the processing of the gpio information (which is inside the kernel, not in userspace), then udev or SDL2, is the only source of lag before the data is processed by the emulator
  • USB : again, let'.s not bither with mechanics. The info has to be processed by the onboard chip, send the right info through the usb, then processed by the usb-hid kernel module, udev/sdl2 then emulator

I'd say the gpio is slightly faster as the processing preceding the emulator is a bit shorter.

A while ago i tried increasing the kernel rate (known as the Hz patch) + switch the context environment (server/desktop/realtime) ... I wouldn't say i found any miracle, but worse : ES constantly had micro stutters