Unifi USG-3P capping at 100 Mbps

Hi there,

I have just downloaded and installed Openwrt to run on an Ubiquiti USG-3P (octeon snapshot build). It runs with no apparent issues, and I installed Luci for the web interface.

When doing more exhaustive tests, I have discovered that the device is handling at most 100 Mbps traffic. The internal switch in the device is Gigabit, and in fact when running stock firmware it can easily achieve 900 Mbps without problems.

I have fiber at home and I have tested that the connection is working OK and this is not an operator problem: I connected directly to the operator's router, it gives 1 Gbps.

I'd like to know if this limitation on Octeon hardware is a known limitation, and if/when it will be solved.

This is my first post on this forum, so please bear with me if this is not the right place to ask for help or report problems with current software.


First thing I would do is determine whether this is an issue with the internal switch or the router cannot handle the traffic: do you have any 100Mbps device connected to the router? is traffic between devices inside the network also affected?

Well I think I can discard problems with the internal switch.

Since changing firmware on this hardware is so easy (just replace an internal pendrive), I have done both tests. As I said, with the original firmware (and exactly the same hardware setup), it gives 1 Gbps, but with Openwrt just 100 Mbps.

The only connections to the router are the WAN connection (to the operator router - blinking on green, which means 1Gbps link speed), and the LAN connection (to another internal Netgear gigabit switch, also blinking green, indicating 1 Gbps link).

I know the links are both correct and at 1 Gbps because I had some trouble with overheating some time ago, and the internal switch changed to 100 Mbps link speed - but it turned yellow, which is not happening now).

The only thing that changes between both setups is the firmware. I have ensured that.

P.S. Thanks for the fast response!

I used to love this device, or actually its Edgerouter cousin, the ER-Lite. Really got me into networking and tinkering with routing.

The USG-3P/ER-Lite uses an ancient SoC that relies on proprietary hardware acceleration (which was buggy for years and caused UDP packet loss) to reach gigabit speeds. It does not have a built-in hardware switch (like the Edgerouter ER-X for example), just 3 separate ethernet ports.
On OpenWRT, the hardware acceleration does not work, so you're left with the performance of software based routing on a 500-ish MHz MIPS chip.

If you want gigabit routing on this device, stay on the official firmware. If you want OpenWRT at gigabit speeds, get a device with an SoC from this decade instead one made in the 2000s. I really like the NanoPi R6S for something that can do 1+Gbit with SQM and at low power.

1 Like

OK, thanks so much, Arie, this was exactly the answer I was searching for.

Since Ubiquiti is not giving so much love to cheap routers lately, I'll start my quest for a new, more powerful router.

Thanks again.

Mmmm, thanks for the pointer frollic, but I'm already in the "component-based setup case". My home setup includes 2 Unifi APs, 3 small Gigabit switches plus the USG-3P.

I was just thinking of replacing the USG firmware with something more powerful (i.e. Openwrt), but then this software-switching issue appeared... I'll replace the USG with something better. The USG seems to have a good second hand price, so I believe I will be able to just switch it for better HW for no additional expense.

I was running a USG with the Unifi firmware until quite recently (I upgraded to the UDM-Pro). As has been noted, it is actually a reasonably powerful 1Gbps routing device when used with the stock firmware, although yes, the features are a bit limited compared to the more modern Unifi devices and of course OpenWrt.

What is is that you are looking for when it comes to the "more powerful" featuers that OpenWrt or other non-unifi firmware may offer?

Well, Linux based... possibility of additional packages... and support. Unifi is on its way of abandoning these devices and is not providing an evolution for my use case: a nerd's house. They are steering me towards SME equipment, which I do not want to buy, it's expensive.

For way less price, I can get an Openwrt-compatible router and have all functions.

Yeah, the USG is basically a dead-end in terms of development . And the Unifi firmware (which is linux based, btw) offers very little in the way of additional packages. The basic firewall features are fine and you can actually do a bunch with it, although it's not quite as full featured for advanced/granular things as you'll find on OpenWrt or other router OSs.

However, the reason I was asking is that it depends on what you want to do with your border gateway device generally and OpenWrt specifically. For example, I run OpenWrt behind my UDM-Pro. In my case, it serves as a VPN endpoint for a road-warrior type config. In this way, my OpenWrt router device doesn't need to be all that powerful (CPU wise) to serve the need, since I'm not relying on it for primary routing. So how you structure your network and the services running on the various devices, and of course the cpu/ram/storage requirements in those devices, will very much depend on your specific goals. If you want to do IDS/IPS type stuff, the USG will not cut it due to the internal bandwidth limitations (unless you are <40Mbps ISP speed, see this), even with the Unifi stock firmware. Generally, you need a lot of horsepower to do IDS/IPS, so you'd likely be looking at a higher end ARM or an x86 class system. Ad-blocking and the like can be done behind your main router with an OpenWrt device running AGH, or somethign else like PiHole, and those only require modest CPU (although RAM and flash storage are more important here).

The point here is that once you have/provide more specifics about what you want to do with your router, you can opt to run it on the border or maybe run it behind, and that can then influence the hardware choices for your application.

This topic was automatically closed 10 days after the last reply. New replies are no longer allowed.