So I've been trying to figure this out for a few years now. I can't handle it anymore.
I'm on ADSL with Vodafone, my Vodafone station modem (the one with the screen) syncs at 7.26Mbps down and 0.86Mbps up. The speeds I get from www.speedtest.net range between 0.38-0.62Mbps down and 0.60-0.72Mbps up with ping between 100-300ms the worse results are taken from today at 5pm and the better results from midnight the same day.

These speed issues have plagued me for years, every time I contacted Vodafone they put me through the isolation tests including me sending them ping/path ping/tracert test results from different times of day and to multiple websites. Those tests didn't amount to much.
To isolate the issue I've tried:
-changing the filters
-removing all phones
-removing everything but the modem (with filter and without)
When I tested the speeds I only had one PC connected to the modem with an Ethernet cable with no other downloads running.
There is no difference between test results when using wifi or an Ethernet connection.

In the end Vodafone said they would log a fault with chorus. From what I understood Chorus came back and said the exchange was congested. Since the speed doesn't get faster than 1Mbps (getting to that speed only happens very late at night around 3am) I can't see it as simple congestion.

So I figure something might be wrong with my wiring, but I thought my isolation test and good sync rates would show that it's not that.

tldr: is my wiring or my exchange the source of my woefully slow internet

Here is a "diagram" of my house wiring (I can do commissioned work for very competitive rates).


Edit: My neighbours get pretty poor speeds too, but that could just be that all of our wiring is bad. This rural in Marahau, near Motueka, Nelson. Also I may have made a mistake on the top speeds I was getting, I just did another test at 1am and it got 70ms 2.44Mbps down and 0.81Mbps. If I manage to get a better speed than that I will update again.