A Ubiquiti Cloud Gateway Ultra that gives slow internet speeds is usually limited by a feature that inspects traffic, the link speed of a port or the line itself, and the first test is to run a wired speed test from a computer connected directly to the gateway with a short cable. Compare it with the plan you pay for. If the wired speed is close to the plan, the gateway is fine and the Wi-Fi is the limit; if the wired speed is low, look at the gateway and the line.
The checks in more detail
Connect the computer to the gateway's LAN port and the gateway to the modem or ONT by a Cat 5e or better cable, and check that the port links at the speed it should in the UniFi Network application. The features that cost the most speed are Intrusion Detection and Prevention, deep packet inspection and some traffic rules. On a gateway of this size, turning on every security feature at once can reduce throughput noticeably on a fast line,
so test with Intrusion Prevention off for a minute, then back on with a lighter set of categories. Smart Queues can limit the speed if configured with a figure lower than your line; check that the rate you entered matches the plan, and turn it off to test. Look at the device's CPU in the application while running the test. The modem or ONT may be the limit, particularly if it supports only a gigabit port on a faster plan, or if the cable is damaged.
Try another cable and port. If the wired speed from the modem directly to the computer is also low, contact the provider. Check that the gateway runs current firmware, since Ubiquiti has made routing throughput changes in updates. A guest network or VPN client can also limit speed if used. For Wi-Fi, the access points have their own channel and width settings, which matter separately. Contact Ubiquiti with a support file if the wired speed through the gateway is low with all heavy features off.
Differential
Likely causes of “Ubiquiti UniFi Cloud Gateway Ultra internet or Wi-Fi is slow”, and how to tell them apart
- 1
Intrusion Prevention or inspection
What separates it Wired speed is lower than the plan
How to confirm Lighten the categories or turn it off to test
- 2
A Smart Queues limit set too low
What separates it Speed capped below the plan
How to confirm Correct or disable the rate
- 3
A slow port or cable
What separates it The link is below the expected speed
How to confirm Use a good cable and check the port speed
- 4
The modem or the line
What separates it Speed is low without the gateway
How to confirm Contact the provider
- 5
Wi-Fi limits
What separates it Wired is fast but wireless is slow
How to confirm Check the access point channels
Before you touch a setting
Record this first — changing settings destroys the evidence
- When the problem started and what changed
- Any message on the screen
- Whether it happens in every app
- The model and serial number
Try in this order
0 of 6 completedTest with a wired computer
ReversibleDirectly on the gateway.
Check the port link speed
ReversibleIn UniFi Network.
Turn off Intrusion Prevention
ReversibleTo test.
Check Smart Queues
ReversibleAnd the rate set.
Try another cable
ReversibleAnd port.
Contact Ubiquiti
ReversibleWith a support file.
Model-specific
What is true of this model and not of its siblings
- Throughput
- Features share the gateway's CPU.
- Smart Queues
- A rate that is too low caps speed.
Stop boundary
When this stops being a self-service repair
- !If the steps do not clear it, contact the maker with the model and serial number
- !Back up important data before a reset
- !Check the warranty before paying for a repair
Evidence ledger
Sources behind this answer
Exact questions
Common questions
Why is my Cloud Gateway Ultra slow?+
A heavy feature, a limit or the line.
Does Intrusion Prevention slow it?+
It can.
Is Wi-Fi separate?+
Yes.
Should I test wired?+
Yes, first.