Factorio Forums

My upload speed is 10Mbit/s and their download speed is about the same. Why does factorio keep slowing it down to a crawl?

I have the same issue. It's okay on smaller maps, but on the bigger ones....

The speed was appropriate in our tests, so there is probably some specific.
Is it faster in the start and then slows down? Or is it just the same slow speed all the time?

Can you provide the log file? What country is there? Is there some specific network settings that might be related?

I've noticed this as well.

It was a 6MB map and the upload started at about 50-100KB/s and slowly rose to about 200KB/s by the end of the upload. I have a 20Mb/s upload speed so I should have been able to get an around rate of around 2.5MB/s.

I was the hosting the server (Didn't tick peer-to-peer) and nobody else was on the server except my friend who was joining. The server has been up for a few hours before that and my friend had just restarted Factorio after a disconnect which wouldn't reconnect.

I've attached the log, or at least I believe it's the correct log.

kovarex wrote:The speed was appropriate in our tests, so there is probably some specific.
Is it faster in the start and then slows down? Or is it just the same slow speed all the time?

Can you provide the log file? What country is there? Is there some specific network settings that might be related?

We get this time to time Kovarex where the user starts at really low speed and then near the end very slow speed. At this point we ask them to alt f4 and reopen the game and it sometimes fixes it. Normally for us we start at like 1.5mbps or whatever the correct caps are and then ends up at 2.1 (so faster)

But yeah this odd bug seems to be a hit and miss but annoying neverless.

For me and my friend it's the other way around.
Start at 300kbps-ish and slows down gradually, meaning that on a larger map it can slow down to 30kbps-ish

Just wanted to bump this thread.
Having a similar issue with 12.26, wondering if it is computer specific?

On my Windows 10 laptop I will start downloading a map at 1.2 mb/s (WiFi) and then quickly crawl down to 20 kb/s, taking 15 minutes to download the map.
On my Windows 10 desktop I will download the map at 1.5 mb/s (Ethernet connection) and it will stay there until finished.

It is also important to note that this is all on the same network - so upload/download is only limited by the router's ability and individual computer network cards (Correct?)

I don't have access to the logs right now, but maybe I can post them when I get home.

0.12.29

Speed starts out fine at 800 kB/s (consistent with my internet subscription dl speed) but drops quickly to 80 kB/s

Yesterday I had the same problem so I started shutting down bandwidth eating services ending up only having factorio (stand alone zip package) running. I even disabled windows updates (and yes, I've long since disabled the windows update peer-to-peer sharing)
I ran some speed tests on my broadband and I even copied the save zip on the server and published it via apache, used a browser to fetch it over http - speedy as ever, it's not my internet, it's not the connection to/from the server it's most likely factorio...

So at this point I started tcpdumping the udp traffic when I connect to see if I could find anything interesting but lo and behold - it started working with normal speed again, random! Happily killed some biters and then went to sleep - this was a ~20 MB save

Today when I try to reconnect I decided to tcpdump again, this time actually capturing a slow sudden drop to 80 kB/s, it eventually desynced once I got into the game so I restarted the server and captured that too - I downloaded the save via http once again and went on to try another connection (still capturing with tcpdump)

Now, looking at the network dumps I can't really see anything useful but perhaps you can? (drop me a public key and I'll set you up to get access to the wire dumps)

Edit*
This morning I had a near perfect download of my now 30 mb save, joined in a few seconds compared to minutes last night, captured it as well if it's interesting to look at

This happens to my group of friends. However only when a third player downloads the map. It starts off at the maximum download speed of 2mbps but rapidly degrades to 10kbps. The hosts upload speed is not being maxed out. The download speed immediately increases when the second player disconnects. Both player 2 and 3 are on the same LAN however 1 is hosting the dedicated server from their home.

The most likely cause of this is the use of UDP for transferring the map instead of TCP. I believe this is a known issue, I'll try to find the thread.

EDIT: I don't see it anywhere "official" in this subforum, so I guess I can't consider it a "known issue".

Using UDP is not the problem, problem is that our implementation was a little messed up.

I've made another fix for 0.12.31, so let's hope this one will be the last that is necessary.

I think the point about TCP was that it takes care of packet loss and transfer speed for you, so it can work fast "out of the box", at the price of being more rigid (less customizable).

But it's great to hear the network code implementation is being improved!