“How many days of footage do I get?” — the most-asked question, answered honestly.

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The short answer

Roughly one week, from an 8TB surveillance drive, across about five 4K cameras.

That’s a real anchor from real installs, and it’s the number to start from. Then read the rest of this page, because five variables can move that week to three days or to a month, and anyone who gives you a precise figure without asking about your building is guessing.

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Three things to know before anything else

1. Recording is local. There is no subscription to record or watch. Your video lives on a drive in your building. No monthly fee to store it, none to watch it, and you can still view it from your phone anywhere in the world. You buy the drive once.

(To be precise: core UniFi, meaning Network, Protect and Access, including all local recording, carries no subscription. Ubiquiti does sell paid extras. CyberSecure is a network-security add-on offered on some gateways, and Official UniFi Hosting is a monthly subscription that runs the UniFi Network controller on Ubiquiti’s infrastructure. Neither has anything to do with recording or retention, and nothing on this page depends on either. Hosting the controller does not move your footage: it still records to the drive.)

2. Drives are not included. Ever. A UNVR arrives as an empty box with four empty bays. A UDM-Pro arrives with one empty bay. The drive is always a separate line item — on our quotes and everybody’s. If a quote for a camera system doesn’t have a drive on it, it isn’t finished.

3. More days = a bigger drive. Not a better recorder, not a faster network. Retention is almost entirely a drive-size question.

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The five variables

1. How many cameras. Straight arithmetic. Double the cameras, halve the days.

2. Resolution. The big one. Look at what a single UDM-Pro does with different cameras: 24 HD cameras, or 14 at 2K, or 8 at 4K. Same box. One 4K camera eats roughly three HD cameras’ worth of storage. This is the lever with the longest handle — and see why 4K isn’t always better.

3. Frame rate. Most G6 cameras record 30 FPS. The G6 180 does 20 FPS and the G6 Pro 360 does 24 FPS — which is one reason those two are gentler on a drive than their megapixel counts suggest. Fewer frames, fewer bytes.

4. Motion-triggered vs continuous. Continuous records everything, always — predictable, and the most expensive. Motion-only records when something moves, and can multiply your retention several times over.

But motion recording’s saving depends entirely on the view, and this is where estimates fall apart. A camera on a quiet back gate might trigger four times a day and keep months. The same camera pointed at a busy street, or a tree that moves in the wind, or a driveway where headlights sweep past all evening, records nearly continuously and keeps a week. Same camera, same drive, wildly different answer.

5. What’s actually in frame. Video compression works by storing what changed. A still hallway compresses down to almost nothing. Rain, snow, blowing leaves, or a busy road means every pixel changes constantly — and the file sizes climb. A Calgary winter with snow blowing across the lens is genuinely harder on storage than a still summer night.

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A worked example

Read this as a method, not a promise.

The setup: five 4K cameras, recording continuously, one 8TB surveillance drive.

Now watch what moves it:

Change	Rough effect	Result
Starting point: 5× 4K, continuous, 8TB	—	~7 days
Add a second 8TB drive (16TB total)	Double the space	~14 days
Switch to 5 cameras at 2K instead of 4K	Roughly a third of the data	~3 weeks
Go from 5 cameras to 10 at 4K	Twice the cameras	~3–4 days
Switch to motion-only on quiet views	Highly variable — could be 3×	~3 weeks (if the views are quiet)
Switch to motion-only on a busy street	Barely triggers less than continuous	~7 days — no change

Every one of these is an estimate. They’re honest arithmetic from a real anchor, not a specification. Your actual retention depends on your views, your weather, and how much moves in front of your cameras. We size drives with headroom for exactly this reason — and after a couple of weeks running, your system will tell you your real number, at which point you’ll know rather than estimate.

Sizing it backwards

Most people don’t want a drive size — they want a number of days. So work it in reverse:

Two weeks on five 4K cameras is about 16TB. A month is about 32TB. That’s when the drive bays matter — the UDM-Pro has one bay, the UDM-Pro-Max has two, and a UNVR has four. Bays cap your retention just as hard as camera count caps your recorder. It’s the same decision, viewed from the other end.

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Surveillance drives vs desktop drives — and why the cheap one fails

This is where people try to save $80 and lose their footage.

A desktop drive is built for a computer. Which means it’s built for idle: it spins up when you open something, does a burst of work, and goes quiet. Engineers rate them for a duty cycle of a few hours a day.

A camera system never idles. It writes continuously, from every camera, forever. No pause, no quiet night, no weekend off. That’s not a heavier version of the desktop job. It’s a different job.

Two things kill desktop drives in this role:

1. Duty cycle. Rated for hours per day, asked for 24. A drive rated for 2,400 hours a year, run 8,760. It doesn’t fail on day one — it fails in month fourteen, which is worse, because by then you’re relying on it.

2. SMR — the one that really bites. Cheap desktop drives use SMR (Shingled Magnetic Recording): the data tracks overlap like roof shingles to squeeze more in. Writing to one track means rewriting its neighbours. It’s fine for storing files you rarely touch. Under a constant write load it collapses — the drive spends its life rewriting itself, throughput craters, and the recorder starts dropping frames. The camera looks like it’s working. The footage isn’t there.

Surveillance drives are CMR (Conventional Magnetic Recording) — tracks don’t overlap, so constant writing stays fast. They’re also rated for 24/7 duty, built for the vibration of several drives in one chassis, and tuned to prioritise keeping the stream going over recovering a perfect block.

The rule: surveillance-rated, CMR, always. WD Purple, Seagate SkyHawk and equivalents. Never an SMR drive, never a desktop drive. We supply them at cost — there’s no margin in it for us, and it isn’t a place to save.

The failure mode is what makes this non-negotiable. A desktop drive in a camera system doesn’t announce itself. It fails quietly, in month fourteen, and you find out on the one morning you actually needed the footage.

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Which recorder holds how much

	Drive bays	Ubiquiti’s stated capacity
UDM-Pro	1× 3.5″	(24) HD / (14) 2K / (8) 4K cameras
UDM-Pro-Max	2× 3.5″	(50) HD / (25) 2K / (15) 4K cameras
UDM-Beast	2× 3.5″	(100) HD / (60) 2K / (40) 4K cameras
UNVR	4× 2.5″/3.5″	Up to 30 days for (18) 4K or (60) Full HD cameras
UNVR-G2-Pro	8× 2.5″/3.5″	Up to (50) 4K or (100) Full HD cameras
UCG-Max / UCG-Fiber	NVMe SSD, up to 2TB	(15) HD / (8) 2K / (5) 4K cameras

Prices (all-in, CAD): UNVR $430 ($399 base + $31 surcharge — cart-verified). UDM-Pro-Max $926 ($859 + $67 — cart-verified). UNVR-G2-Pro $1,548 ($1,435 base + $113) — derived, not cart-verified, and Sold Out; treat as indicative only. UDM-Pro $588 ($545 base + $43 surcharge — cart-verified). Drives are extra in every case.

Ubiquiti’s checkout adds a per-unit memory surcharge that’s invisible on the product page — the UNVR’s $399 becomes $430 in the cart. That’s why the store looks cheaper than our quote. More on that in the gateway guide.

Note the UCG-Max and UCG-Fiber: an internal SSD capped at 2TB. Against our 8TB-for-a-week anchor, that’s a small pool. Fine for a couple of cameras and a few days. Not a video retention plan.

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Related

• Choosing a Gateway — drive bays, and the limit that bites first
• Choosing Cameras — resolution, frame rate, and why 4K costs you days
• Glossary — CMR, NVR

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Retention is a question about your views and your weather, not just your drive. If you’d like a real estimate for your building — and a drive sized to the days you actually want — AVNFi can work it through with you.