When the internet is slower through a UniFi Dream Machine SE than the plan promises, the cause is usually the gateway's security features, a rate limit that was set too low, the modem or the provider, and a systematic test finds it. First measure properly. Run a speed test from a wired computer plugged into the UDM SE, not over Wi-Fi, and compare it with the same test made directly from the modem if possible. If the modem is as slow, the provider is the problem.
The checks in more detail
If the speed is fine at the modem and slow through the gateway, the gateway is limiting it. The UDM SE has a powerful processor but intrusion detection and prevention, deep packet inspection and some traffic rules limit throughput, particularly on a fast fiber line. Open Settings, Security, Protection, and turn off IDS and IPS for a test, then run the speed test again. If the speed rises, the filter was the limit, and you can tune it: reduce the categories, choose a less aggressive mode or accept the trade-off.
Check Settings, Internet, Smart Queues: if the download and upload rates are set below your plan, they cap the speed, so set them close to the plan or turn them off for a test. Look at the traffic rules and the traffic identification feature, which add processing. Check the WAN port. The UDM SE's WAN can be a gigabit port, a 2.5 gigabit port or an SFP+ port, and a plan faster than a gigabit needs the 2.5 gigabit or SFP+ ports, since a gigabit port caps at gigabit.
Check that the port negotiated the right speed and that the cable is good. Update the firmware, since throughput improves in updates, and restart. Slow speeds on Wi-Fi only are an access point matter, not the gateway. A slow speed at certain hours points to congestion at the provider. If a test from the modem is also slow, call the provider with the results. Keep a record of the tests with times. Ubiquiti's community can help with the logs and settings.
Differential
Likely causes of “Ubiquiti UniFi Dream Machine Special Edition internet or Wi-Fi is slow”, and how to tell them apart
- 1
IDS, IPS or deep packet inspection
What separates it Throughput falls through the gateway
How to confirm Test with them off and tune
- 2
Smart Queue rates set too low
What separates it Speed is capped below the plan
How to confirm Set them to match the plan
- 3
A WAN port that cannot carry the plan
What separates it Speed stops at one gigabit
How to confirm Use the 2.5 gigabit or SFP+ port
- 4
The modem or the provider
What separates it A direct test is slow too
How to confirm Contact the provider
- 5
Wi-Fi limits
What separates it Only wireless is slow
How to confirm Check the access point
Before you touch a setting
Record this first — changing settings destroys the evidence
- The speed from the modem and through the gateway
- The WAN port and speed
- Whether IDS or IPS is on
- The Smart Queue rates
Try in this order
0 of 6 completedTest wired
ReversibleAt the modem and through the gateway.
Turn off IDS and IPS
ReversibleAs a test.
Check Smart Queue rates
ReversibleAgainst the plan.
Check the WAN port
ReversibleSpeed and cable.
Update the firmware
ReversibleAnd restart.
Contact the provider
ReversibleWith the results.
Model-specific
What is true of this model and not of its siblings
- IDS and IPS
- They limit throughput.
- WAN port
- A gigabit port caps at gigabit.
Stop boundary
When this stops being a self-service repair
- !If the modem is slow too, contact the provider with the results
- !Ask Ubiquiti with logs if the gateway is the limit
- !Turn IPS back on after testing
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why is my speed lower through the UDM SE?+
IDS or IPS or a rate limit.
Which port for a multi-gigabit plan?+
The 2.5 gigabit or SFP+ port.
Should I test over Wi-Fi?+
No, test wired.
Is the provider slow?+
Test at the modem.