Author Topic: Jerky spaceship movement in multiplayer...  (Read 1952 times)

Offline AnimaLMotheR

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Jerky spaceship movement in multiplayer...
« on: June 21, 2011, 04:02:54 PM »
Aloha all..

I have an issue which I cant seem to solve by searching the forums. A group of us started playing the game again after a prolonged break. Using Hamachi we connect to the host and everything is fine until the game proper starts. Thats when units start exhibiting "jerky" movement. All of us would get it and it would disappear upon my disconnecting from the server. I can run the game in single player just fine. No jerkyness.

Apparently the "WAIT" message was appearing next to my name every second. We looked at our FPS ingame and they did fluctuate a lot (10-100FPS) for both myself and the host. The game speed on my end was also very very low, at around 30%-40%. No amount of fiddling with the game profiles would increase the speed. In single player, the speed is 100%.

Something similar to this was happening to me on a version of the game prior to the switch to Unity engine. But that was solved by switching the affinity to one core. This fix does not work with this problem.

BTW, its only the units that move which are affected by the jerkyness. The background is moving smoothly (planets spinning etc.), the force fields are also spinning smoothly but if I recall correctly the wormholes were jerky.

AMD Athlon 64 X2 4600+ 2,4GHz
nVidia 8800GTS
2GB of RAM

I think that is it.. Thanks in advance. :)

Offline x4000

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Re: Jerky spaceship movement in multiplayer...
« Reply #1 on: June 21, 2011, 04:11:16 PM »
The visual jerkiness is based around the game simulation running too slowly -- the fact that backgrounds and such are still scrolling smoothly is a very good indicator that it's not your CPU or GPU that are the limiting factor, since it's still drawing as fast as it can but the game itself is unable to proceed.

Normally that could be an indicator that someone else is the problem and your game is just having to wait to catch up (that's why the other players' ships are jerky), but in this case since the wait message is appearing next to your name on the host's machine, that means that the problem is that everyone else is waiting on you.

Given that changing the performance profiles didn't affect anything, that just confirms what I said above, that the problem isn't with your CPU or GPU.  That's why changing the affinity also didn't do anything, because actually your CPU is probably idle quite a bit at the moment while all that jerkiness is going on.

The actual problem, by process of elimination, is therefore a networking issue.  That's also consistent with the fact that you're playing full speed in single player, where there's no networking involved.  Given that, what you'll want to do is run through the steps outlined under "Dealing with a network bottleneck" here: http://www.arcengames.com/forums/index.php/topic,74.0.html

At worst, you should be able to increase the network skip to the point that the game becomes playable.  Ideally, if there is an updated LAN driver you can get for your computer, or if lowering the MTU setting helps, or if you are on an unreliable wireless network connection that you can get off of, or if there are a bunch of background uploads/downloads on your computer or your network that you can stop... (whew, long sentence).  Anyway, one of those ought to do the trick.

Hope that helps!  And if there are further questions, obviously feel free. :)
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Offline AnimaLMotheR

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Re: Jerky spaceship movement in multiplayer...
« Reply #2 on: June 21, 2011, 05:20:58 PM »
Danke danke for your quick reply. I will try out the network skip next time we start a game. Unfortunately there are no newer versions of drivers for the NIC so there is nothing I can do there. Also, no real gamer uses a wireless connection. :)

Offline x4000

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Re: Jerky spaceship movement in multiplayer...
« Reply #3 on: June 21, 2011, 06:11:39 PM »
My pleasure!

I'd also suggest checking your router firmware if you can -- sometimes if that is out of date, the QoS settings can be causing troubles.  Sounds like it's probably not the NIC.  You could also reduce the MTU setting slightly in the game, although it's unlikely to be the problem.  Actually, the host would need to lower their MTU inside their copy of the game, too, to have that work.  Try 1400 or 1390 and see if that makes any difference before you go to network skip.  We have that setting in there to work around really unusual ISPs or routers that use a lower MTU on their networks, but for most networks that would not be a problem.

The network skip causes an increase in command lag (the amount of time between when you issue an order and that order happens), but keeps the game simulation moving smoothly.  That's why it's usually best to find the actual network bottleneck first, but if that fails the network skip is a surefire way to get rid of the jerkiness if it's network-related.  A low network skip (5 or 6 at highest) is almost not noticeable, but a high network skip (in the teens) can make for some impressive "radio delay," heh.
Have ideas or bug reports for one of our games?  Mantis for Suggestions and Bug Reports. Thanks for helping to make our games better!

 

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