Retroarch Latency settings

[TheMadMan007]

So it appears with the new Retroarch 1.7.2, they added a new Latency option that really helps with lag, where it is actually better than even the original systems. Sadly, RetroArch has a horrible issue of never providing any documentation on how to actually use any of the cool stuff they add. I've heard people say "just turn it on" but there are quite a few "on" settings, and I'm not really sure what to turn on and what to leave off. Should I change any of the other numbers or options?

Hard GPU Sync: Defaults to off

Hard GPU Sync Frames: Defaults to 0

 Frame Delay: Defaults to 0

Audio Latency (ms): Defaults to 64

Poll Type Behavior: Defaults to Late

Run-Ahead to Reduce Latency:  Defaults to Off

Number of Frames To Run-Ahead: Defaults to 1

Runahead Use Second Instance: Defaults to Off

 

I have a very good PC, i7, 32GB DD4, 1080ti, so should I be using GPU sync at all and any other changes I should make?

[bundangdon]

I was also curious about this, so I did a little bit of research

From one of Retroarch's pages on the same subject: https://www.libretro.com/index.php/retroarch-1-7-2 - achieving-better-latency-than-original-hardware-through-new-runahead-method/

"Once the game is running, go to Settings -> Latency and/or Quick Menu – Latency. The setting ‘Run-Ahead to Reduce Latency’ is what you want to enable. From there on out, you can specify the amount of frames that you want to run ahead. Be advised that how well this will work with the game in question will depend on the game’s built-in amount of lag frames, so experimentation is key here."

I'll test this out myself a little later tonight and see how well it does

 

Edited April 27, 2018 by bundangdon

[spektor56]

https://www.libretro.com/index.php/retroarch-1-7-2-released/

How to check the amount of lag frames a game has

RetroArch has the ability to pause a core and advance it frame by frame. Perform the following steps to determine the amount of lag frames of a game:

• Pause emulation (press ‘p’ button on keyboard).
• Press and hold the jump button on the controller.
• Advance emulation frame by frame (press ‘k’ button on keyboard) until the character jumps.

The number of k presses before you get a reaction should be the number of lag frames you can safely remove with run ahead.

[Lordmonkus]

Set Hard GPU Sync to On

Hard GPU Sync Frames to 0

Frame Delay set to as high as you can without hearing any audio crackling, if you set it too high and get audio crackles dial it back til the sound gets good again. This will be a per core and maybe per game setting if you really wanna be that specific with it.

Audio Latency set to as low as you can set it without hearing audio crackle.

Run ahead is the new "hackish" way of reducing input lag and you will need to experiment with it. You will need to play around with it to get the exact number you want on a per core basis.

All of these will impact performance some so you will have to tinker to find the best settings for your PC, the defaults are a good safe middle ground so that even lower end hardware is fine out of the box.

[rudi]

can these settings also be used on my PI3 arcade,i have some trouble with lag in games to?

[Lordmonkus]

You can try them but those settings are for input latency, not frame rate issues.

[neil9000]

28 minutes ago, rudi said:

can these settings also be used on my PI3 arcade,i have some trouble with lag in games to?

Pi 3 is real weak hardware, these settings will probably make it worse.