retropie + RPI 3B+ vs RPI 4

Heya's..

Just wondering if anyone can comment on RPI4 performance running various emu's on retropie.

Specifically in Kung Fu Master (if you guys remember this classic), when the enemy grabs you, you shake the stick left n right to shake em loose.. But I'm noticing a bit of lag between inputs and thus it doesn't work.

Would an RPI4 be better for this ?? Or is it possibly the fact I'm running through the GPIO connectors using GPIOnext as the mapping software.

Could a USB encoder eliminate this, or would it add more delay ?

Cheers for any input.

 

Lag comes in many forms, and tracking down the cause might not be as simple as one thing.

A faster machine can certainly decrease lag, although that is quite emulator dependent. Other things to try are different displays (particularly if you're running your Pi on a domestic TV with all sorts of terrible post processing which ads lag). Testing on a good quality PC gaming monitor might be worth it just to rule that out.

I haven't heard of GPIO controls being any worse than USB HID. I works assume they'd be better in fact, although I don't know what the polling/sample rate is.

Dig through this guide too, and see if any of it helps:
https://github.com/RetroPie/RetroPie-Setup/wiki/Input-Lag

 

3b+ should be plenty for Kung Fu Master. I couldn't get the gpio controls to work, so just went the USB route.. I'll test it out tomorrow if I can spot any lag. I've got a pi 4 aswell waiting for a possible upgrade as I do notice some slowdown in alien vs predator, but that's a few gens later than KFM.

 

do you you have a 4 way joystick? (can you just swap in a different restrictor?)
https://retropie.org.uk/forum/topic/16518/arcade-joystick-adjustments/7

 

Main differences between Pi3 + and Pi4

* Proper Ethernet on Pi4, as Pi3 was a USB implementation that shared the USB bus
* Pi4 can have more than 1GB of memory, always a good thing.
* Pi4 has USB3
* Pi4 has newer CPU
* Pi4 has better graphics

Does any of this matter for RetroPi? elvis has explained it else where (search forum).

IMO and only my opinion moving the network off the USB bus big win for USB bus comms, USB3 also big win, finally 4GB memory big win.

Running a graphical interface with 1GB depending on other software has always been Pi3 Achillies heel, especially browsers, don't notice it as much with 4GB.

 

Hmm, duh, jetlag moment there (for myself), i was referring to frameskip, not lag.. sorry..

 

I Googled - GPIO of the first gen RPi was 125MHz, which is more than ample for a game controller. GPIO won't be the problem.