PSA: Possible source of controller/input lag

vtjdailey

After spending an enormous amount of time trying to figure out my lag problems with the retropie, I figured I would post my results and solution in case it might save someone else some time.

I've configured my NES emulator with the settings in this thread:
https://forums.libretro.com/t/an-input-lag-investigation/4407/399

This worked great....sometimes...... I've had horribly inconsistent results -- sometimes the controls felt nice and tight and platformer games were no problem. Then next time I'd play there would be terrible, unplayable lag. I fiddled with a million different settings and nothing seemed to work long term.

FINALLY, I discovered that if the tv was already on the retropie HDMI input when I powered it on, it worked fine. If it was on the blueray player when I powered it on, and I switched it over to the retropie input, I got lag. Totally 100% reproducible problem and solution.

I can't say for sure exactly what the problem is, but I strongly suspect the TV has a bug in it's software with the 'game mode' setting. I believe it checks the game mode setting when it boots up, but fails to re-check and apply a new setting when switching inputs.

It's a Vizio TV I bought sometime in 2012 or 2013. I don't know how many other TVs might exhibit this behavior but hopefully this message can save some time for anyone else struggling to get playable, lag-free input. At least it's one more thing to try when you're banging you head against the wall thinking, "this was just working two days ago!".

Reroshaggy

@vtjdailey Does your tv have a "Game Mode" option, and does it properly activate this option switching from bluray to the arcade source? Bluray players are great with all the extra processing and color/sound adjustments modern tv's have, game systems not so much. Forgive me if this is all known to you, just trying to nail down the problem.

toychotomy

I know this is an old topic but please bear with me!

First of all, I can't thank you enough for this post. Seriously. This was exactly my issue and by following the advice above, Retropie emulators now run nearly lag-free (at least, for me)! The insane part is that I would have never, ever, found this solution on my own.

I own a Vizio E601I-A3, purchased sometime around the end of 2012. I use a Logitech remote control to start the TV and receiver by way of a couple macros. Each of those two macros is assigned to two HDMI inputs, neither of which is the HDMI input used by my Raspberry Pi 3. Because of this, whenever I turn the TV on, it always starts up using an HDMI input not connected to the Raspberry Pi; I would then use the TV's input selection to switch over to it which would cause the exact behavior described above! And since I had no reason to ever start the television on the RPi's HDMI input, I never knew this was causing the problem.

Every game was suffering from input lag and not just a little! Any platformers, shooters, pretty much anything that requires fast reflexes was more or less unplayable. When playing something like a Mario Game, you could tap your thumb on the jump button and lift it completely before the onscreen action would respond. I'd estimate the latency to be nearly a half second. So many others were online gushing over how well their Retropie setups performed, and my own seemed almost useless for all but a handful of games.

I've been poring over this forum and a handful of others for literally hours over the course of the past week, trying every random suggestion (Game Mode of course, refresh rate changes, Vsync, various video drivers, video threading, etc.), even repeating some solutions 3 or 4 times, basically banging my head against the wall. Nothing was working and I was extremely frustrated. I looked up my particular TV model online and found wholly positive remarks regarding input lag in general. To this end, I have my Xbox One and PS4 connected to the same TV and have never experienced the same issue (as they were started properly on their own discrete HDMI input, as above). As you can imagine, to my eyes that meant that if my TV was fast, and I'd tried everything under the sun to improve performance in Retropie, surely the issue was with the Rpi itself, and everyone else was just dealing with this HUGE input delay!

I was nearly about to give up, and had decided that the Retropie setup would henceforth be relegated to only RPGs, puzzlers, and slower-paced games. By pure luck and on a whim, I happened to take one final stab at finding a solution by including the word "Vizio" in my search and I stumbled onto this thread.

@vtjdailey, thank you so much! I am certain others with Vizio TVs have run into this exact same problem, but judging from the low amount of views your post has received, I'm not so sure many others were lucky enough to find the solution. I'd go so far as to suggest that you change the thread title, if possible, to something like "Input lag solution for certain Vizio TVs" as I can confirm that this is definitely not an isolated issue.

chipsnblip

great find! i added a note in the wiki here: https://github.com/RetroPie/RetroPie-Setup/wiki/Speed-Issues#tv

i hope the wording is clear enough. if not feel free to suggest changes (or edit them directly).

toychotomy

@chipsnblip I think that's worded very clearly. Thank you!