Lag in 0 AD - A Few Questions

[2fftr]

If I posted in the wrong section, or if this is a commonly discussed topic please tell me and link me to the relevant sections / threads.

Over time I've introduced a few friends to 0AD, and one reaction I've invariably got, is that the lag makes the game a bit of a frustrating experience. Every time I play I notice that actions are carried out after a short delay, and especially troop movement gets more and more delayed as the game progresses. I remember reading somewhere that the pathfinding is a performance bottleneck and that it is being improved, but I'm not sure, it could very well be performance issues of my own computer causing the lag. Searching the forum for "lag" returns no results for some reason.

My questions are:

• Is this a general issue of the game, experienced by others, or is it me playing on outdated hardware and slowing the game down for everyone in my multiplayer games?
• If it is indeed a general issue, what causes it? What is being done to address it?

Edited February 12, 2020 by 2fftr

[Stan`]

1. Yes it's a general issue of the game. The speed of the game is conditionned in multiplayer by the slowest computer in the bunch. The game is a CPU intensive task which is mostly mono threaded ( As in not able to use more than one CPU core) Since in MP all the clients compute the game the AIs and whatnot on their own they have to sync regularly so the slowest computer defines the pace. Also in MP "turns" are slower than in SP (200ms per turn vs 500ms)
2. I believe I answred most of it in the above post. There is some work being done to improve things for A24 mainly threading the pathfinder and the networking and @vladislavbelov is working on making the renderer a bit faster. (The renderer is also a bottleneck)

Welcome to the forums @2fftr

[Boudica]

The lag can be made bearable by avoiding some match setting options:

1. High population limit. I remember times when the population cap of 150 was the norm for 4 vs. 4 games. Lower population games teach players how to cooperate better and they aren't any less fun. What isn't fun is when the game starts running at a third of its normal pace.
2. Maps with a big amount of trees. Too many trees are hard for both the pathfinder algorithm and the renderer. When you select from Random maps, which are popular among advanced players, you can typically select a biome that is easier for the CPU. At least avoid the Tropical biome, or try going for Savanna and Desert options to be sure.
3. Large map sizes. Again, I can remember times when we used Medium map size for eight player games. Yes, the strategy is a bit different, but it still isn't unfair to anyone and it isn't any less fun. You avoid situations when an ally dies too fast and you are unable to come help because of the huge distance. When you consider how much fun even a tiny map 4 vs. 4 game can be (those are called pizzas and the real pros love those), I don't see a reason to consider the smaller map size as limiting.
4. Maps with many obstacles and impassable areas. Units can get stuck on the choke points and it's not generally easy for the pathfinder when there are too many units at one place.

Thinking about it, there are quite a few known ways to reduce the lag, which makes me ask why we play with lag settings so often. I guess having a fast game isn't a real priority for quite a lot of hosts. It's similar to the typical lobby waiting time. People don't care that 20 minutes pass and the game hasn't yet started. I don't really know who introduced these norms.

[2fftr]

Thank you for your replies. It is nice to see that work is being done on the issue, really looking forward to the next alphas. In the meantime I will be sure to take your remarks into account when hosting games Boudica. I already limit population caps and map sizes, but never thought about tree quantities and the like.