Factorio Forums

Bandwidth upload drops severely when 2x or more connect to a server at the same time (or during one of the users connections. This causes the server to immediately choke on the upload to the other user and both drop down to half if not 1/10th of their ability to download from the headless server. Just a heads up

Is it the same user causing you to slow down every time? I regularly run with 3-4 people (who all have great connections) and Factorio runs smoothly.

Check viewtopic.php?f=23&t=27466. If even one person has slow internet, it's going to bog down the server. This is intended functionality to prevent the slow user from desyncing. Hope this helps.

Thanks for the report,

It seems like a specific router/network configuration issue