Emulator

I have an Xbox one S controller too, but to me the rumble bahaviour in Super Mario Sunshine seems pretty much the same as with the original Xbox controller (no lag)...

forgot to say that I use the controller usb wired

No lag even though your controller is also emulating 2nd GCN ctrl's rumble?

I've tried wired, no dice, but maybe I need to restart my PC to confirm this?

Okay! My memory is bit hazy to where I tested wired.

I tried Super Mario Sunshine wired, it rumbles erratically. I must have tested Brawl with it and thought the GCN games will stil lag, but turns out I'm wrong, the result is GCN games will do like Wii games when I'm on wired.

I think it's all "Dinput/0/Bluetooth XINPUT compatible input device" doing

I've just tried it with bluetooth connection and still no lag...

Isn't this an issue with the xbox controller and how it polls?

I have only one controller, so maybe that lag is due to bluetooth not "keeping the pace" of two controllers connected?

I can still reproduce this even my DS3 is not in use. By lag, the whole emulation lags, not rumble lag. It'll be more noticeable in rumble intensive GCN games.

I tried run two Dolphin instances, ran Super Mario Sunshine, Xbox's rumble became more active when each Mario are doing things differently, no whole emulation lag or erratic rumble.

Maybe you're not replicating this issue correctly? Only one controller, Xbox One S controller, to emulate two GCN controllers' rumble function, not two controllers to emulate one GCN controller, or maybe you're not actually on bluetooth when going "wireless". Do you happen to have dongle for Xbox controller?

My PC is i7-7700K with GTX 670. I'll try PCI bluetooth I have in my i7-2600K PC I haven't salvaged it to my i7-7700K PC. Though I really doubt my bluetooth is the problem. I'll try on different PC also, it's a i5-4690K PC with iGPU.

Okay, I've added PCI bluetooth and the emulation got better, but is that really true? Is it normal that the bluetooth has the ability to slow down the emulation?

I forgot that my i5-4690K is running Windows 8.1, Xbox One S controller requires Windows 10.

I've noticed the title and all "rumble lag" mention are bit misleading, it's emulation that lags when Xbox One S controller is rumbling while it's emulating two GCN controllers' rumble function.