lag lag lag, I hate it, just ran a lag test and am disappointed with RPi/retropie

mediamogul

vs average of 3.5 frames lag RPi

There will always be some amount of lag in an emulation setup. A lot of people are thrilled when they shave lag down to 3.5 frames. There's only a handful of games out there that are so time sensitive and it's possible that even they can be beaten with a little more practice than is normally required. For example, forum member @RumblinBuffalo just beat Mike Tyson without any real regard to lag-specific settings at all.

Anybody got any ideas how to reduce lag on the RPi?

I've seen these tips recommended over time:

Overall:
Use a CRT Television
Disable all post-processing features, or switch to 'Game Mode' on a LCD TV
Wired controllers
Dispmanx where applicable

RetroArch:
video_driver = "dispmanx"
video_threaded = "false"
video_frame_delay = "5"

dankcushions

@rig said in lag lag lag, I hate it, just ran a lag test and am disappointed with RPi/retropie:

USMC

what's this?

perhaps if you tried it via the AV out rather than your hdmi > CRT setup.

also, 3.5 frames is actually very good for emulation. if you see https://forums.libretro.com/t/an-input-lag-investigation/4407 you will see that even windows gets this sort of figure. it used to be a lot worse!

i think you'll struggle to get an improvement from there.

rig

@dankcushions Thanks! yea people are telling me that these are good results. I guess my expectations are high. I will research how to implement these settings
RetroArch:
video_driver = "dispmanx"
video_threaded = "false"
video_frame_delay = "5"

Is "video_threaded = "false" video_frame_delay = "5"" altered in the config file?, I am guessing "video_driver = "dispmanx"" is enabled through retropie config menu....is that right? I will run another lag test as soon as I try these new settings.

I am using a crt tv; I don't use the the hdmi port I use a hat board that outputs vga. the vga is then sent to the USMC (you can find them at arcade forge online, they're pretty cheap) which combines the H and V sync from the vga signal and outputs rgb with composite sync to a scart cable that goes to my monitor. I have been told that the USMC and the hat board introduce zero lag, this method is preferable to utilizing a hdmi to vga converter because (as I have been told) that method introduces lag. I also use a wired ps2 controller. Thanks again!

pjft

@rig I believe all of them can be changed in the RetroArch menu. You do need to save them for turn to be applied when you restart RetroPie, so depending on your setup you may want to go straight to the config files for that after you're happy with the results.

Is there any particular emulator you're using as well, though? In my previous experiences with SNES, there is a noticeable difference in terms of input lag between some emulators, at least in Super Mario World there's one of the emulators in which I just can't play it as the timing is completely off for me at least. I don't have the name of the top odds my head, but if input lag is part of your concerns then try that as well.

Still, 3.5 is a great number.

rig

@pjft Yeah thanks I was able to find all the retroarch settings, make the changes and run the test again. I ran the test with the RPi without the retroarch alterations (lag was an average of 1.7 frames), I then ran it with the the retrtoarch alterations (lag was an average of 1.3 frames). and I ran the test again with original hardware (lag was an average of 0.5 frames)

My numbers were really low this time. I did a few things different: I did the test in the morning, as apposed to late at night when i was tired; I sat right in front of the monitor really close; I did 10 practice/throw away lag tests before I recorded the 5 tests that I averaged to get my data; I used the same monitor (my sharpest monitor) for all the tests, I noticed that It was getting better times on my sharp monitor (it is easier to align the two shapes during the lag test with a really sharp monitor)

I am a little shocked how good the numbers were, especially after multiple people have been telling me that 3.5 frames is a good number.

so there was a slight advantage to using the retroarch settings. Will these settings cause any problems with emulation? compatibility?etc? Thanks guys, this was fun to tinker around with

mediamogul

@rig said in lag lag lag, I hate it, just ran a lag test and am disappointed with RPi/retropie:

Will these settings cause any problems with emulation?

The biggest consideration I can think of is that using dispmanx in RetroArch prevents the use of shaders and overlays, but aside from looking really nice, they would add a frame or two of lag, so it would go against your main goal here to begin with. Also, any of the yellow onscreen text will not be visible, making notifications from features like RetroAchievements impossible. That aside, I have to say 1.3 and even 1.7 frames of lag is quite impressive. Many thanks go out to everyone who made that possible.

Edit: I'd be interested to hear if you're able to beat the 'Clinger Winger' stage on 'Battletoads' with this setup if you ever get around to it.

rig

@mediamogul Thanks man; I can live without shaders. I will definitely attempt Battletoads with the pi. I typically pass clingerwinger first try with original hardware but I have never been able to pass it with an emulator. I am pretty excited about it actually. probably happen next week. I let you know.

maxriptide

I have a RPi3 with Gert-VGA + UMSA scart adapter hooked up to a Sony PVM CRT Monitor and I use the following settings on retroarch.cfg for Megadrive and PC Engine emulator:
video_threaded = "false"
vsync = "true"
video_hard_sync = "true"
video_frame_delay = "10"

My results with the 240p Suite Manual Lag Test are approximately 0.5 frames for both emulator which is the same value I get with the real consoles hooked up to the same monitor. With the same test on the SNES emulator (I don't own a SNES) I get approximately 1.5 frames lag.

BuZz

@maxriptide video_hard_sync = "true" has no effect on the RPI btw. Vsync should be enabled by default.

maxriptide

@BuZz didn't know that, thanks

rig

@maxriptide you know what. Your the third person to point out that the snes emulator is prone to lag. I will try again with my sega setup. For some reason i couldn't get the genesis 240p test suite to work with the pi so i gave up.

Thanks for responding. I was hopeing someone could duplicate my results. Our data is really close. Cool.
How does the "frame delay" work. It can't actually be delaying video ten frames. I wonder how this would effect fighting games. Does it delay frames from the player? Does it delay frames from the npc? Both?

maxriptide

@rig to be honest I really don't know how it works, maybe someone in the forum could explain that, all I know is that after using these setting I found on the web I got rid of the lag. I should also try to remove the video_hard_sync = "true" line since, as BuZz wrote, it should not have any effect on the RPi.

AndersHP

@pjft said in lag lag lag, I hate it, just ran a lag test and am disappointed with RPi/retropie:

@rig I believe all of them can be changed in the RetroArch menu. You do need to save them for turn to be applied when you restart RetroPie, so depending on your setup you may want to go straight to the config files for that after you're happy with the results.

Does this mean that they wont be applied unless you save and restart? Or do they apply instantly but get reset if not saved? Sorry if it's a stupid question.

rig

@AndersHP said in lag lag lag, I hate it, just ran a lag test and am disappointed with RPi/retropie:

@pjft said in lag lag lag, I hate it, just ran a lag test and am disappointed with RPi/retropie:

@rig I believe all of them can be changed in the RetroArch menu. You do need to save them for turn to be applied when you restart RetroPie, so depending on your setup you may want to go straight to the config files for that after you're happy with the results.

Does this mean that they wont be applied unless you save and restart? Or do they apply instantly but get reset if not saved? Sorry if it's a stupid question.

I believe that the changes are applied immediately but as soon as you exit the game/retroarch you lose the changes unless you save them. You can verify this by making changes, exiting the menu and the reentering the menu and checking to see if your changes are still there.