Which UniFi brain do you need — and why the cheap one so often turns into an expensive one.

---

1. What IS a gateway? (And what’s a “UDM”?)

The gateway is the brain. It’s the single box where your internet arrives and where your whole system is run from. It does three jobs at once:

1. Router — decides where traffic goes, between your building and the internet.
2. Firewall — decides what’s allowed in. This is your front door to the internet.
3. Controller — the software that manages every other UniFi device you own. Your Wi-Fi settings, your camera settings, your door rules: they live here, not in the cloud.

And on some models, a fourth job:

1. Video recorder — an actual hard drive inside the box, recording your cameras.

The analogy: the gateway is the front desk of a building. It’s the only way in or out, it checks everybody’s ID, and it’s also where the staff directory, the key register and — in the bigger buildings — the security tape room live. A small building can put all that at one desk. A big building can’t, and it’s not a moral failing, it’s just physics.

“UDM” means UniFi Dream Machine — Ubiquiti’s name for its all-in-one gateways. UDM-Pro, UDM-SE, UDM-Pro-Max, UDM-Beast are all rack-mounted UDMs. The small white desktop units are named differently (UniFi Express, Dream Router, Cloud Gateway) but do the same core job at a smaller scale.

Every UniFi system has exactly one gateway. It’s the first thing you choose and the last thing you want to replace.

---

2. The decision table — the whole range

Specs from techspecs.ui.com. Prices from ca.store.ui.com, checked 2026-07-16. See the pricing note below the table — the store is not showing you the full number.

Model	Throughput (IPS/IDS)	Max clients	Max UniFi devices	Max Protect cameras	Drive bays — records video?	Built-in Wi-Fi	PoE ports	Form	Price (all-in, CAD)
UX (UniFi Express)	Not published	50+	4	No — not published as Protect-capable	Yes	None — no bays. No.	None	Desktop	Not in our verified price data
UX7 (Express 7)	2.3 Gbps	300+	30+	No — not published as Protect-capable	Yes	None — no bays. No.	None	Desktop	Not in our verified price data
UDR (Dream Router)	1 Gbps	150+	20+	(5) HD / (2) 2K / (1) 4K	No 3.5″ bay — limited internal recording only	Yes	2 (40W total)	Desktop	Not in our verified price data
UDR7 (Dream Router 7)	2.3 Gbps	300+	30+	(5) HD / (2) 2K / (1) 4K	No 3.5″ bay — limited internal recording only	Yes	1 (15.4W total)	Desktop	Not in our verified price data
UCG-Ultra	1 Gbps	300+	30+	No — not published as Protect-capable	No	None. No.	None	Desktop	Not in our verified price data
UCG-Max	2.3 Gbps	300+	30+	(15) HD / (8) 2K / (5) 4K	NVMe SSD up to 2 TB — yes, but small	No	None	Desktop	Not in our verified price data
UCG-Fiber	5 Gbps	500+	50+	(15) HD / (8) 2K / (5) 4K	NVMe SSD up to 2 TB — yes, but small	No	1 (30W total)	Desktop	Not in our verified price data
UDM-Pro	3.5 Gbps	1,000+	100+	(24) HD / (14) 2K / (8) 4K	(1) 3.5″ bay — YES	No	None	Rack, 1U	$588 all-in — cart-verified ($545 + $43)
UDM-SE	3.5 Gbps	1,000+	100+	(24) HD / (14) 2K / (8) 4K	(1) 3.5″ bay — YES	No	Yes — 180W budget	Rack, 1U	Not in our verified price data
UDM-Pro-Max	5 Gbps	2,000+	200+	(50) HD / (25) 2K / (15) 4K	(2) 3.5″ bays — YES	No	None	Rack, 1U	$926 ($859 base + $67 surcharge — cart-verified)
UDM-Beast	25 Gbps	7,500+	750+	(100) HD / (60) 2K / (40) 4K	(2) 3.5″ bays — YES	No	None	Rack, 1U	$2,319 all-in — cart-verified ($2,150 + $169)
UCG-Industrial	5 Gbps	500+	50+	(15) HD / (8) 2K / (5) 4K	Not published — assume no bay	Yes	Yes (PoE+ and PoE+++ ports)	Wall / desktop / rack (accessory)	Not in our verified price data
EFG (Enterprise Fortress Gateway)	12.5 Gbps	5,000+	500+	Not published as Protect-capable	None. No.	No	None	Rack, 1U	Not in our verified price data
EF-Core (Enterprise Firewall Core)	79 Gbps	22,500+	2,250+	Not published as Protect-capable	None. No.	No	None	Rack, 1U	Not in our verified price data

Reading the camera column: “(24) HD / (14) 2K / (8) 4K” means the same box handles 24 low-resolution cameras, or 14 mid-resolution, or 8 at 4K. It’s one budget spent three ways — not three separate allowances. Most cameras people actually want are 4K, so read the last number and ignore the first two.

About those prices

Ubiquiti adds a per-unit “memory surcharge” at checkout. It doesn’t appear on the product page. It’s only itemised in the cart. So the store looks cheaper than it is.

Example: the UDM-Pro-Max shows a base of $859, and the surcharge adds $67 — $926 all-in, read from the cart. That’s the number that matters.

Where the surcharge applies, it runs 7.43–7.89% — consistent across all 29 SKUs we’ve cart-verified. But some products carry none at all, and the category doesn’t tell you which: a USW-Flex-Mini switch and a $1,005 UVC-AI-MS-2 camera both come up $0. The only way to know is to read the cart, so that’s what we do — never a calculation. See pricing.

AVNFi always quotes all-in. Where we’ve written “basis unconfirmed” above, the store price we captured may be a base figure that will grow at checkout — we won’t state a number we haven’t verified in the cart. Where a model shows “not in our verified price data”, it simply isn’t in the price file we maintain; ask and we’ll price it live.

---

3. The expansion question — read this one twice

This is the mistake we see most, and it costs the most to undo.

Here’s how it goes. Someone buys a small desktop gateway. It’s cheap, it’s tidy, it works beautifully. Eighteen months later they want two cameras at the back gate.

And they discover the box they bought can record one 4K camera. Total. Ever.

Where the cliff actually is

There are four separate limits, and they do not run out at the same time. Ranked by which one bites first:

1. Protect cameras — this is almost always the first wall. It’s not close.

• UX / UX7 / UCG-Ultra: not published as Protect-capable at all. This isn’t a small allowance — there’s no allowance. Adding cameras means adding a separate recorder (a UNVR), or replacing the gateway.
• UDR / UDR7: one 4K camera. One. A doorbell and a single camera and you are finished.
• UCG-Max / UCG-Fiber: five 4K cameras — and onto a small internal SSD, so see the storage guide before you cheer.
• UDM-Pro / UDM-SE: eight 4K cameras, onto a real 3.5″ hard drive you choose.
• UDM-Pro-Max: fifteen 4K, onto two drives.
• UDM-Beast: forty 4K.

A modest house — front door, back door, both sides, garage, driveway — is six cameras. That number sails straight past everything below the UDM-Pro. A small office with a back alley is easily the same.

2. Drive bays — the limit behind the limit. Camera count is one thing; how many days you keep the footage is another, and that’s decided by drive size. A gateway with no 3.5″ bay can’t take a large surveillance drive, so even if the camera count fits, your retention may be a few days rather than a few weeks. Verified: UDM-Pro has 1× 3.5″ bay, UDM-Pro-Max has 2, UDM-Beast has 2 — all three record video natively. Gateways without bays need a separate UNVR recorder alongside them.

3. UniFi device count. Every access point, every switch, every camera, every door hub counts as a device. The UX allows 4. Four. A gateway, a switch, and two access points and you’re done — before a single camera. UDR/UCG-Ultra/UCG-Max sit at 30+; UDM-Pro at 100+. This one bites second, usually on bigger houses with several access points.

4. Throughput and client count. Realistically, last. If you have a 1 Gbps internet plan, a 3.5 Gbps gateway is not your bottleneck, and “1,000+ clients” is a number a home will never approach. Do not buy a bigger gateway for the throughput number. Buy it for the drive bay.

So why does the cheap desktop unit become a dead end?

Because the gateway is the one component you can’t add to. You can add a switch. You can add access points. You can add cameras. But there’s exactly one brain, and when it’s full, the upgrade path is buy a whole new brain — the original spend doesn’t get credited, it gets shelved.

The honest framing

If cameras are genuinely never happening — a rental, a small office that will only ever have Wi-Fi — the small desktop units are excellent, and we’ll happily sell you one. The failure isn’t buying small. The failure is buying small while quietly planning big.

There’s a middle road too: buy a small gateway now and add a UNVR (a standalone recorder) when cameras arrive. That works. It costs more than having bought a UDM-Pro up front, and it’s two boxes instead of one, but it isn’t a dead end. Just decide it deliberately instead of discovering it.

---

4. What’s it compatible with — and what isn’t

Compatible with:

• Every UniFi switch and access point. Any gateway adopts any UniFi switch or AP, up to its device limit. Mix and match freely.
• UniFi Protect cameras — but only if the gateway is Protect-capable (see the table), or you add a UNVR.
• UniFi Access door hubs and readers.
• Older UniFi gear. Wi-Fi 5 (AC) access points still adopt and run perfectly on current gateways. They’re not obsolete.
• Whatever internet you have. Fibre, cable, or a modem from your provider — the gateway sits behind it.

Not compatible with — and this is where money gets wasted:

• Third-party cameras. UniFi Protect records UniFi cameras. Your existing brand-X cameras will not appear in the app. There’s no adapter.
• Third-party access points. They’ll pass traffic if you plug them in, but they won’t be managed, won’t roam properly with UniFi APs, and won’t appear in the app. At which point, why.
• Each other. One gateway per site. Two gateways is two separate systems, not a bigger one. To grow you add switches and access points, never a second brain.
• Cloud video recording. Protect records to a drive in your building. That’s a feature, but it means the drive is yours to buy and yours to size. (The controller is a separate question: Ubiquiti does sell cloud hosting for UniFi Network. See below.)
• Drives. Not included. Not with any of them. A UDM-Pro arrives as an empty bay.

Worth knowing: the UDM-SE is the only gateway in the mainstream rack lineup with a real PoE budget of its own (180W). Every other rack model needs a PoE switch beside it to power your cameras. Don’t assume the gateway can power anything.

---

5. The other half of the range: independent gateways and hosted controllers

5. The verified facts, in one place

Three claims we’re prepared to be held to:

• UDM-Pro: one 3.5″ drive bay. Records video natively.
• UDM-Pro-Max: two 3.5″ drive bays. Records video natively.
• UDM-Beast: two 3.5″ drive bays. Records video natively.

And the corollary: a gateway without a drive bay needs a separate UNVR to record cameras. No exceptions, no firmware update coming.

---

6. Just tell me which one

Your situation	Buy this	Why
Small home — Wi-Fi, a handful of devices, a doorbell at most, no camera ambitions	UCG-Ultra or UX7	Genuinely enough. Cheap, silent, no rack needed. Accept the trade: you are choosing “no cameras, ever” without a rethink.
Big home — several access points, a few cameras, a doorbell, wants it to last	UDM-Pro	The drive bay is the whole reason. Eight 4K cameras and a real surveillance drive covers the overwhelming majority of homes. Needs somewhere to rack it.
Small office — 20–40 people, a couple of cameras, maybe a door reader later	UDM-Pro, or UDM-Pro-Max if the door and camera list is already growing	1,000+ clients and 100+ devices is far more than a small office reaches. Again: buying it for the bay, not the speed.
Camera-heavy site — a dozen-plus 4K cameras, long retention	UDM-Pro-Max (15× 4K, two drives) or UDM-Beast (40× 4K)	Two bays means more storage and the option of redundancy. Past 40 cameras it’s a UNVR conversation instead.
Fibre straight to the building, no cameras	UCG-Fiber	5 Gbps and an SFP+ port to take the fibre directly. Only if cameras really aren’t coming.
You already own a small gateway and now want cameras	Keep it, add a UNVR	Cheaper than replacing the brain, and you keep what you paid for. Two boxes instead of one.

If you only remember one line

---

Related

• Storage and Retention — how many days of footage a drive actually holds
• Choosing Cameras — what you’d be recording
• Switches and PoE — what powers it all
• Glossary — any word above that didn’t land

---

The right gateway depends on your building, your internet, and honestly on what you’ll want in three years — which is a conversation, not a table. AVNFi is happy to have it.