Netplay Desync

02-07-2014, 03:56 PM #1

My friend and I plan on playing some single player games together over netplay (one of us plays, the other watches), and earlier today we tried Eternal Darkness for the first time. After having no problems connecting, we realized that my friend (who wasn't playing at the time) had a good 15 second delay (whatever I did showed up about 15 seconds later for him). Everything was still synced, it was just he had that delay. What I'm assuming is that since I didn't set any controllers for him in the netplay window, that he had a delay to not have any impact on the people that could've been playing (could be wrong here, but it's the only thing I could think of why that delay was there, makes some sense when thinking about it because spectators don't play and don't have any impact on the game whatsoever). We fixed this by just restarting everything. Any reason why this happend? or is it what I thought it was? Also, we're not sure if his game just started late.

Other than that, we did have one desync after playing about 10 minutes after fixing that delay above. The buffer was set to 10 I believe (we only live 10 minutes apart, ~25ms ping) so I'm sure it could be set to lower if we wanted. We were both using 4.0.2 with the recommended settings for netplay either disabled or enabled. Is there anyway to prevent this in the future, or is it just a random occurrence that may or may not happen again?

**RachelB** · (This post was last modified: 02-07-2014, 04:30 PM by RachelB.)

Dolphin makes absolutely no attempt to make sure each emulator is running at the same speed. It doesn't know, or care, if others are ahead or behind. Normally, if a player has a controller mapped, if they fall too far behind, the buffer that holds controller input for that player will be empty, and so everyone connected will pause and wait for input to be received from them. However, if they do not have a controller set, then it will not be waiting for input from them, so they can fall behind without affecting anyone else. They will stay in sync because the buffer will simply accumulate all of the inputs from other players, and play them back as it needs to. The solution is make sure all emulators run at the same speed. If that's not possible, you can pause yours for a bit, and let him catch up, then resume, though of course you'll need to do that periodically, as he will continue to fall behind again.

02-07-2014, 04:47 PM #3

Would an easier fix be just to make sure we both have controls mapped to us?

**JMC47** · 02-07-2014, 05:03 PM #4

If he's on a spectator, you can set the buffer to 0, and have no ill effects. His computer is just slower, and thus, falls behind as you play.

**RachelB** · 02-07-2014, 05:51 PM #5

(02-07-2014, 04:47 PM)crynryan Wrote: Would an easier fix be just to make sure we both have controls mapped to us?

Then you would lag.

02-08-2014, 11:47 PM #6

After a couple more attempts, we had another desync while just normally playing, and after that it was fine for a good 45 minutes until we switched games. With the new game, we desynced in the same spot (Luigi's Mansion, during the tutorials) twice. We tried both times having both of us having controls mapped to us, and the other without and it still desynced.

How tolerable of packet loss is Dolphin? I'm assuming that I'm dropping too many packets since my wireless adapter is a cheap $20 adapter (I don't have any way of getting wired, powerline adapters don't work well where I'm at either), and my friend is wired.

**RachelB** · 02-09-2014, 03:24 AM #7

(02-08-2014, 11:47 PM)crynryan Wrote: How tolerable of packet loss is Dolphin? I'm assuming that I'm dropping too many packets since my wireless adapter is a cheap $20 adapter (I don't have any way of getting wired, powerline adapters don't work well where I'm at either), and my friend is wired.

It uses tcp.

**JMC47** · 02-09-2014, 06:00 AM #8

Luigi's Mansion use zelda-ucode HLE, so you may have to switch to LLE audio for it to switch. fwiw, Netplay should never desync if you're configured right, and I've played a ton of games for 2 - 3 hours or longer and had no issues.

02-09-2014, 02:07 PM #9

We're pretty sure we have the configuration settings right, after following the netplay window prompt, and we have the same graphics settings set.

golem09 · (This post was last modified: 11-03-2015, 09:49 PM by golem09.)

Sorry for necroing this, but I have the same problem, with the same game, and I thought writing here would better than a new thread.

I'm playing Eternal Darkness with my girlfriend as a spectator (latest revision from last night), and she is falling more and more behind, while getting no desyncs at all. Reading here that it's actually about emulation speed, would it help if she just lowered her graphic settings? Playing in 720p instead of 1080 and without AA for example?