Chasing full 5-gig fiber with a Ubiquiti UDM Pro Max
Got AT&T 5-gig fiber last week and set out to actually pull the full 5 gig through a UDM Pro Max. Sharing what I found, because the IPS throughput really surprised me. The Pro Max couldn't do it — not with IPS on.
- IPS ON: download bottlenecked around 2.0–2.2 Gbps. It'd spike to ~3G for a split second, then always fall right back to ~2. Upload sat around 4.1 Gbps.
- IPS OFF: download came up to 3.8–4.2 Gbps. Upload was still ~4.1G either way — IPS didn't seem to touch upload.
So even with IPS off I couldn't hit the full 5-gig, and with IPS on I was stuck at ~2G — despite the Pro Max being marketed as ~5 Gbps with IPS. That threw me.
To rule out my own hardware, I ran a local OpenSpeedTest and pulled 9.8 Gbps up AND down, no problem — so my NICs, cabling, and switching clearly weren't the bottleneck. That left the gateway's IPS/routing as the only suspect.
I ended up upgrading to the UniFi Dream Machine Beast (UDM-Beast) — rated 25 Gbps IPS/IDS. First speed test: 5.2 down / 4.8 up — and both numbers were still climbing when the test ended. Pretty sure a longer run would've pushed them higher. Basically full symmetric 5-gig, right out of the gate.
Next step: rip out the AT&T BGW620 gateway and drop a WAS-110 XGS-PON SFP stick straight into the UDM Beast, and see if I can squeeze out a little more.
Takeaway: if you're on multi-gig fiber and want IPS on, look at the real single-flow IPS throughput, not the headline number — the Pro Max's ceiling was way below its rating for me, and it took a bigger box to actually deliver 5-gig with inspection on.
The UDM Beast is actually a beast. I also have a couple of 25-gig devices — an MS-02 Ultra running Proxmox and a Synology with a 25-gig NIC — so that's a huge plus; I originally had those two directly linked to pull max speed for my backups.
Anyone else hit the IPS wall on the Pro Max at multi-gig? Curious what you're seeing.