Gateways+ trade routes = massive performance drop

[Jaydonium]

I was playing on a small galaxy, I just got gateway build tech, so I figured sweet. I can eliminate piracy by putting a gateway in all my trade starbases. About 10 gateways total would be needed.

On gateway 4 performance tanked hard. But I persevered. I finished all 10, but now the game is unplayable as theres 3-4 seconds delay with each click or action. Pausing the game eliminates the delay instantly.

I went and tested it on a new save, built 8 gateways around my home system, as soon as I built another trade starbase the performance tanked, and my empire was only 10 systems.

I tested on hive mind, I was able to colonize the whole galaxy and build roughly 100 gateways without performance issues.

So yeah, don't ruin a 10 hour game by building gateways to eliminate piracy. Unless you are hive mind. Then build all the gateways you please.

 

[Dodonpa]

Probably, distance calculation is causing a thing.

In my case, 4 trading hub with Gateway caused no problem but if I increased the trading hub to 5, it caused a slight freeze.

 

[krios41]

yea... i'm also having huge performance issue's after i began constructing gateways.
at least, i began to notice performance drops after that... its a meme by this point, but that save is currently literaly unplayable

 

[Orimichi]

It's not the subject but if you build gateway you don't need other trade hub than your capital no?

 

[Xexus]

@Wiz
Fix plz)

 

[Jaydonium]

I managed to reduce lag by destroying every star base I owned that had access to trade resources. Oddly my empire is still in the green. but all the numbers of trade goods all over the place are kind of annoying.

As a test I built some trade hubs on my capital starbase. The game went back to taking roughly 20 seconds per day with 2 trade hubs. My income went up by 1k though.

EDIT: The game crashed when I got to 4 trade hubs.

 

[Mastikator]

Sounds to me like gateways make the distance finder algorithm go for an endless loop

 

[Astax]

This makes sense. The calculation due to the extra connections must be ridiculous. And no easy way to fix this unless they specificially omit the gateways (not a good idea) or redo how the hubs actually work.

 

[Mastikator]

This makes sense. The calculation due to the extra connections must be ridiculous. And no easy way to fix this unless they specificially omit the gateways (not a good idea) or redo how the hubs actually work.

Finding loops in node trees is a well known problem (and solution), just add a flag that says "I've been here before" when searching through the nodes and stop when you see the flag so you never continue through a node more than once. This is programming 101 and it's probably just an oversight that they'll fix in 2.2.2

 

[MagKel]

Mathematically what could happen is that pathing algorithms are breath-first, which means that for each node the software iterates every path until exhausted, which is very common strategy where O(|V|+|E|) or Linear Time.

No matter how many CPU-cores you have, since gateways are infinite endpoints upon which you can build infinite edges E with V zero, the algorithm loops until it is pushed out of queue for the tick.

 

[A Cat]

Finding loops in node trees is a well known problem (and solution), just add a flag that says "I've been here before" when searching through the nodes and stop when you see the flag so you never continue through a node more than once. This is programming 101 and it's probably just an oversight that they'll fix in 2.2.2

That's probably part of it.

Actually, it almost sounds like this is based on trade hubs which shouldn't even be a path finding deal. Its finding every node within a given distance, so you don't care about paths.

I don't think they should be running the trade path finding algorithm every day either.

 

[My_Devil_Is_He]

Hello everyone! Does anyone has a savegame (without mods pls) with the perfomance issue, so I could look into it?

 

[Quz]

This should do it, since I´ve built gateways my performance dropped extremely.

 

[Typee]

Inb4 the stellaris dev team solves the traveling salesman problem in a polynomial time.

 

[Captain Conundrum]

Is it the trade routes causing this, the collection distance going through gateways, or both? If it is just being caused by collection distance, it might be better to just not allow starbases to collect trade value through gateways and wormholes.

 

[RookieCookieNamNam]

I don't understand, isn't the algorithm just finding a shortest path (A* or something) between a starbase and the capital starbase?

 

[Zag14]

This thread may be usefull, there are few saves with gateways and without gateways and stuttering issue https://forum.paradoxplaza.com/foru...ause-of-ai-pathfinding.1135694/#post-24939892 @My_Devil_Is_He

 

[Jorrhast]

What's there to solve? Specifically for trade routes (which apparently use their own PF algo since patrol routes differ from TRs), quick and dirty fix till they have more time:
1) for GW trade systems, the route is 2-point, direct from here to capital;
2) for non-GW trade systems, ignore all gateways for purpose of PF; after the path is plotted, check for nearest GW system on the path and if there is one, go to p.1.

 

[Captain Conundrum]

I don't think this is a pathing problem. I think every starbase near a gateway is trying to collect nearby trade value by looking at every system within range of every possible exit gateway.

 

[My_Devil_Is_He]

@Quz @Zag14 Thanks!