I have the same promised speed as you, and am a bit perplexed by my speed test results also. I have a UDM-Pro which bridges between the ONT (cat 6) and a Unifi switch (SFP at 1Gbps), and onwards via cat 6 through another switch to a Mac Pro.

Running the Unifi speed test usually gives me over a 1gig result (max I've noticed 1128/120). Testing against fast.com gives me 1.0Gbps (or sometimes slightly more) if IPS/IDS is off and something a bit lower if on.

The reason for my confusion is that my understanding (as recently explained very clearly here, for example) was that this sort of speed should not be achievable. Nice problem to have, I guess

On your USG-Pro-4 have you tried disabling Smart Queues and IPS/IDS?

The figures you are seeing are down to assumptions made in the coding of the different speed testers and people generally being happy so long as they see a bigger number.

If you are using an Gigabit Ethernet interface the maximum TCP/IP throughput is 940 Mbps down and 940 Mbps up.

Yes, I had come to the conclusion that some tests probably gross up for packet headers. But still the conclusion seems to be that that 930Mbps max quoted by BT may not be a real max.

In the end speed tests at this level are only something to be worried about when one is stuck bored at home

Edited by deleted (Tue 07-Apr-20 13:30:49)

My setup is like this ONT --> USG-Pro4 --> UniFi Switch 24 POE-250W. I don’t know if my computer is getting rather old. I tried with a laptop with a SSD still the same results 894Mb download, 119Mb upload.
The Smart Queues and IPS/IDS is disabled on the USG.

Your best troubleshooting option is to test with your computer directly connected to the ONT, then you create a dial up PPPoE connection in Windows (assuming that is what you are using) with your ISP credentials. If you get the same speeds you know it isn't your network equipment being the bottleneck and it is something elsewhere that is most likely outside of your direct control.

If speedtests show the top expected speed when it is just your PC direct to the ONT then you know it is something internal to you and can work from there.

Hope that helps.

I have already tested with BT smarthub 2 connected directly to the ONT. I'll test with the computer attached directly to the ONT.
Thanks,