The issue was happening while I was playing Arumba's Lazy Bastard mass multiplayer game.
Let's start with my computer specs are pretty much out of question: GTX 980Ti, i7-5930K, 32GB ram. I was not downloading anything or uploading anything else (and the issue was happening more often when I didn't watch the stream, so it seems not related to download rate)
It was happening more often with 40-50 current players, not so much when we had 200-250 players.
The game has not ever once dropped me out from poor connection, desync etc (only when Arumba crashed the server
)What was happening: (fps/ups)
- game was running 60/60 just fine
- suddenly fps starts dropping (not instantly but gradually) and stays at around 5/45 to 5/60
- when this was happening I could not move, could not open chest/any inventory/research (if I did, it was closing straightaway, couldn't do any change), fairly often a tile I highlighted was not moving with my mouse cursor but stuck on a tile
- if I was moving when this has happened, my guy's animation was stuck looking like it's moving but didn't actually move at all, if I was on a belt, I was NOT moving on the belt either (from my perspective)
- some other people were playing fine, some reported having similar issue
- I could see other players moving around, building, placing belts, stuff moving on belts, etc - even chat was fine (but anything I sent to chat appeared after issue has gone away and fps started climbing again)
- I could open map and zoom into other parts of the map and see what's going on there just fine (players moving, rocket launching, etc)
- This was happening the most when server player was in the game but not playing (alt-tabbed out?), though was also happening but much less often when he was playing
This could have lasted few seconds up to ~20 minutes! It happened tens if not hundreds of times playing tonight.
What's strange issue often gone away (just for few seconds, sometimes for few minutes) after server saved the game for someone (but not 100% cases)
I don't think it was blueprint related (because when that happened, clients were getting "server not responding" instead)
So what I think could have happened (lots of speculations):
1. Arumba's tabbing out of the game somehow de-prioritised game thread or not enough CPU/resourced to sent it to all players.
Potentially some players were not treated equally when packets were being sent out? Potentially prioritising new players/catching up ones than the ones in the game
2. Something has triggered my game sending more data out (upload), when my upload starts, it can impact the download rate. If that happened and I had no control over it and upload was maxing out, my download rate would be very slow.
But then again I could see other players actions and what's going on around me fine but I just couldn't do anything myself.
3. No other idea atm.
Not sure what could be cause if the issue but it certainly seemed strange as I should have all capacity to play it yet something else was limiting me. Even then I could see everything around me just fine but couldn't interact.
Any idea what could it be? If there's anything else I could help you with. You can use save from the other thread where Arumba posted it (viewtopic.php?f=30&t=44925), or can attach more recent if that helps
