I'd be very keen to investigate further @zespri.

Can you DM me the endpoints you are connecting to, and I'll dig into pathing, and see if our upstreams can be optimised for those paths.

Handy website lol

https://isindigodown.com/

Great to hear - I would have suggested that also but as you said "aria2c" I thought you were perhaps using Linux already so this didn't apply. Windows TCP tuning is terrible on high speed, high latency connections such as what you see to the EU, combined with the cable fault meaning traffic is taking a scenic route on many ISP's currently means the problem is worse than normal.

The problem appears to be caused if you've got a Realtek network card (Wireless or Wired) as for some reason it messes with the TCP/IP tuning on Windows. I've personally purchased an Intel card and disabled my motherboards Realtek card for this very reason and have not seen it occur again.

michaelmurfy:

 

The problem appears to be caused if you've got a Realtek network card (Wireless or Wired) as for some reason it messes with the TCP/IP tuning on Windows. I've personally purchased an Intel card and disabled my motherboards Realtek card for this very reason and have not seen it occur again.

 

Yes both my desktop and my laptop have Realtek network.

zespri:

 

Kids, if you have weird stuff happening on your puter, and no one else reports the same, chances are, that it's local to your system and not someone else's (ISP's) fault.

 

So I was testing my speed on two different computers, so it did not occur to me that it may be configuration related, I was dead sure that the symptoms point to ISP, even after reading Jase2985 results I did not change my opinion. But it happened that I needed to work on Linux this evening, and as a matter of form, I ran the download there. My surprise was great when I saw normal speed not capped at 2Mbps.

 

If it works on Linux then there must be something I can do here. To think about it, the two Windows boxes I tested on, there were both mine, not family members, so I installed the same crap on both and it could be some kind of driver, or something like that, that could have caused it. I tried on my son's Windows PC and it also was fast. I cannot imagine why I have not thought of that in the last several weeks of suffering, I was so sure.

 

So I started uninstalling stuff from one of the boxes, and to be honest uninstalled almost everything but it did not help. So I started googling what can cause slow download speeds in particular on Windows. One of the articles suggested `netsh interface tcp show global` command to check "Receive Window Auto-Tuning Level” and use either `netsh int tcp set global autotuninglevel=disabled` or `netsh int tcp set global autotuninglevel=normal` (depending on what it is currently) to flip it.

 

Mine was "disabled". I changed it to "normal" and my download speed went to normal too. Thank you everyone who participated and in particular to @VygrNetworkMonkey for the gracious offer of help. This is now resolved.

 

Windows tuning is a total nightmare.... it changes randomly.... It's the cause of probably 80% of all speed complaints that are done properly (this is kinda a ballpark figure i'm pulling out from experience at previous providers too.)