The best surveillance hard drive for an NVR, Frigate or UniFi Protect is decided by its workload rating, not the camera count on the box. WD rates the standard WD Purple for up to 64 HD cameras, yet the same drive carries a 180 TB/yr workload rating. That works out to about 45 Mbps of sustained traffic, or about seven 4K cameras at a typical 6.1 Mbps bitrate on writes alone. Plan for six, not 64.
This guide links our PoE camera picks for Frigate to our NAS hard drive rankings. It turns the bitrate your cameras push into a drive size, a workload class and a model that fits your recorder. We compared WD Purple, Seagate SkyHawk and SkyHawk AI against the WD Red Plus and IronWolf Pro NAS drives using their datasheets, Ubiquiti’s storage requirements and the Frigate docs. We did not burn in these drives ourselves, so every spec traces to a vendor page or is flagged where it doesn’t. We confirmed each price, stock state and spec against the live listings in October 2026.
Pick a surveillance drive by recorder
Start from the recorder you already own and how many cameras feed it, because those two facts rule out most drives before price enters the picture:
- Best overall, Seagate SkyHawk AI 8TB: a 550 TB/yr rating and support for 32 AI streams, and it listed for less than the standard SkyHawk 8TB when we checked (about $380 to $385, check the live price).
- Small one or two bay recorder, WD Purple 4TB: CMR, 180 TB/yr, fine for up to six 4K cameras on one disk, around $225 to $230.
- UniFi Protect and big Frigate pools, Seagate IronWolf Pro 20TB: the 7200 RPM CMR drive Ubiquiti’s storage page asks for, 550 TB/yr, roughly $880.
- Frigate on a server that also holds files, WD Red Plus 10TB: 7200 RPM CMR, sold and shipped by Amazon itself, around $460.
Prices on all four moved a lot in 2026, and most surveillance listings come from third-party sellers rather than Amazon. So we priced each pick per terabyte in the comparison table further down. Every section also names the exact model number, so you can match the listing to the datasheet before you pay.
Read the workload rating before the camera count
The workload rating is the ceiling that matters for a recorder, and it is lower than the camera count suggests. WD defines it as the user data transferred to or from the drive per year. Writes from your cameras and reads from playback, exports and Frigate’s review UI all count against it. The 64-camera figure for WD Purple assumes one 1080p H.265 stream at 3.2 Mbps per camera, a light load next to a 4K camera on its default settings.
We converted both workload classes into sustained bitrate and divided by two camera profiles. The 6.1 Mbps profile is Reolink’s default main-stream bitrate on its RLC-810A 4K and RLC-510A 5MP cameras. The 3.2 Mbps profile is WD’s own footnote. The arithmetic below ignores playback reads:
| Workload class | Drives | Per day | Sustained rate | Cameras at 6.1 Mbps | Cameras at 3.2 Mbps |
|---|---|---|---|---|---|
| 180 TB/yr | WD Purple, SkyHawk, WD Red Plus | 493 GB | 45.7 Mbps | 7 | 14 |
| 550 TB/yr | SkyHawk AI, IronWolf Pro, WD Purple Pro | 1,507 GB | 139.5 Mbps | 22 | 43 |
Seven cameras is where a 180 TB/yr drive runs out on writes alone, so we’d plan for six and leave the rest for playback reads. Eight 4K cameras recording 24/7 write about 194 TB a year to a single disk, past the rating before anyone scrubs through footage. Going over doesn’t make a drive fail on the spot. But WD quotes WD Purple’s 1 million hour MTBF at 90 TB/yr and 40°C, so a disk at twice that load runs outside the conditions behind the reliability number. Past six 4K cameras on one disk, step up to the 550 TB/yr class or spread the cameras across two drives.
Size the drive by retention days
Capacity decides how many days of footage you keep, and Frigate makes the maths direct because it writes recordings straight from the camera stream with no re-encoding. Whatever bitrate you set on the camera’s main stream is what lands on disk. At Reolink’s 6,144 kbps default, one camera recording continuously fills about 66.4 GB a day:
| Cameras (24/7 at 6.1 Mbps) | Written per day | 4TB | 8TB | 10TB | 20TB |
|---|---|---|---|---|---|
| 2 | 133 GB | 30 days | 60 days | 75 days | 150 days |
| 4 | 265 GB | 15 days | 30 days | 37 days | 75 days |
| 8 | 531 GB | 7 days | 15 days | 18 days | 37 days |
Most homes with four cameras want two to four weeks of continuous footage. That puts an 8TB drive in the right place, and it is why our overall winner is an 8TB disk. Frigate sets retention in days per mode (continuous, motion, alerts and detections), so you can keep 7 days of 24/7 footage and 30 days of motion clips on the same disk. Segments land in Frigate’s cache before they are kept, so a motion-only setup writes far less than the table shows.
If you have not set Frigate up yet, our Frigate Docker install guide covers the recordings path and retention config.
Compare the four picks side by side
All four picks are CMR, which is the first filter for any recorder because SMR drives slow to a crawl on sustained writes once their cache fills. The columns below are the ones that changed our ranking:
| Drive | Model | RPM | Workload | Cameras / AI streams | Warranty | Approx $/TB |
|---|---|---|---|---|---|---|
| Seagate SkyHawk AI 8TB | ST8000VEZ01 | Not published | 550 TB/yr | 64 HD / 32 AI | 5 yr + 3 yr Rescue | $48 |
| WD Purple 4TB | WD43PURZ | 5400 class | 180 TB/yr | 64 HD | 3 yr | $57 |
| Seagate IronWolf Pro 20TB | ST20000NT001 | 7200 | 550 TB/yr | NAS drive | 5 yr + 3 yr Rescue | $44 |
| WD Red Plus 10TB | WD100EFGX | 7200 | 180 TB/yr | NAS drive | 3 yr | $46 |
The odd one out is price per terabyte. Both surveillance picks cost more per TB than the NAS picks. So the reasons to buy WD Purple or SkyHawk are the surveillance firmware your recorder expects and the camera-stream ratings. The NAS drives win on cost and on the 7200 RPM spec Ubiquiti asks for.
Buy the Seagate SkyHawk AI 8TB for most NVRs
The SkyHawk AI 8TB is the drive we’d put in a typical seven to sixteen camera recorder. It pairs the 550 TB/yr workload class with a price that undercut the regular SkyHawk 8TB on the day we checked. Seagate rates the family for 64 HD streams plus 32 AI streams with a five-year warranty and three years of Rescue data recovery. The 8TB model carries a 2 million hour MTBF; only the 12TB and larger models reach 2.5 million.
Triple the workload headroom is what you’re paying for, and on current pricing it costs nothing extra. The SkyHawk AI product page lists capacities from 8TB to 32TB. The 8TB listing on Amazon (ASIN B08KTM4SNY) sells it as ST8000VEZ01, the retail variant of the ST8000VE001 in Seagate’s datasheet. It was in stock at about $382 from Adorama, a third-party seller, roughly $48 per TB. The standard SkyHawk 8TB (ST8000VX010) listed for about $427 the same day with a third of the workload rating. We’d skip it unless the price flips. Check the live SkyHawk AI 8TB price on Amazon before you buy.
Skip it for a UniFi console in RAID 5 or ZFS. Retailers list the 8TB at 7200 RPM, but Seagate’s datasheet has no spindle speed row, and Ubiquiti asks for a 7200 RPM CMR drive, so we can’t confirm it meets that spec from the vendor. It is also more drive than a two-camera doorbell setup needs. There, the WD Purple 4TB below does the job for less money up front.
Put a WD Purple 4TB in a small recorder
WD Purple 4TB (WD43PURZ) is the drive for a one or two bay NVR, a Blue Iris PC or a Frigate mini PC with a handful of cameras. WD’s product brief lists it as CMR with 256 MB of cache and support for up to 16 drive bays. Its AllFrame firmware is tuned for many low-bitrate streams. Frigate’s own planning docs name WD Purple and SkyHawk as the surveillance drives to consider.
Four terabytes holds about 30 days of two 4K cameras or 15 days of four, which covers most small installs. The Amazon listing (B0C4X6RDV8) was in stock at about $227 from a third-party CCTV seller, close to $57 per TB, the highest of our four picks. That premium is the cost of a small drive in a year when every capacity got pricier. It is still the cheapest of our four picks up front. See the current WD Purple 4TB price.
Skip it past six 4K cameras on the one disk, because the 180 TB/yr rating runs out at seven on writes alone. Skip it for a multi-bay UniFi console too. WD lists the standard Purple as a 5400 RPM class drive, and Ubiquiti says 5400 RPM is not recommended for multi-bay consoles in RAID 5, 6, 10 or ZFS. If you’re building a Windows recorder around it, our Blue Iris PC guide sizes the CPU and GPU by camera count.
Use the IronWolf Pro 20TB for UniFi Protect
Ubiquiti’s storage requirements page asks for a 1TB or larger CMR drive at 7200 RPM in rack consoles such as the UNVR Pro and UDM Pro. The IronWolf Pro 20TB (ST20000NT001) meets every line of it. Its datasheet lists CMR, 7200 RPM, 256 MB of cache, a 550 TB/yr workload rating, a 2.5 million hour MTBF and RAID-tuned AgileArray firmware.
It is also the cheapest terabyte in this guide at about $44 per TB. The listing (B0B94MF4LP) was in stock at around $880 through a third-party seller. One 20TB disk keeps about 75 days of four 4K cameras, and in a RAID 5 array the camera writes spread across every member, so the 550 TB/yr budget goes a long way.
Ubiquiti’s storage health page warns when a new drive’s RPM differs from the ones already installed, so buy matching drives for the whole array. Check the IronWolf Pro 20TB listing for the current price.
Skip it for a four-camera house with one bay, where $880 on a single disk buys months of footage you will never scroll back to. Ubiquiti’s own recommendation is the official UniFi HDD in 8, 16 or 24TB. It is worth pricing if you’d rather keep warranty claims with one vendor. Before you buy a console at all, our UniFi Cloud Gateway comparison shows which models have a drive bay and which take NVMe.
Choose WD Red Plus 10TB when Frigate shares the box
When Frigate runs on a homelab server or NAS that also stores files, backups or media, a NAS drive fits the mixed traffic better than surveillance firmware does. WD describes its Purple Pro line as optimized for sequential video writes rather than mixed file-sharing traffic. That trade-off is why we’d use a WD Red Plus 10TB (WD100EFGX) in a shared box.
The 10TB model is CMR at 7200 RPM with 512 MB of cache, rated for 180 TB/yr and systems up to eight bays. Its Amazon listing (B0F4R3YCL6) is the only pick here sold and shipped by Amazon itself, at about $460 or $46 per TB, which makes returns simpler. Frigate’s docs also prefer local disks over recordings on NFS or SMB shares. A Red Plus inside the Frigate host beats pointing Frigate at a separate NAS. Check the WD Red Plus 10TB price.
Skip it in arrays larger than eight bays, which is past WD’s rating for Red Plus. Skip it too when a single disk takes more than six 4K cameras, since it shares WD Purple’s 180 TB/yr ceiling. For larger NAS drives ranked by price per TB, see the full NAS hard drive list.
Avoid the SMR and mystery-SKU listings
Surveillance drives carry the same brand label across CMR and SMR models, so the model number on the listing is the only thing that tells you what you’re getting. We hit four traps while checking stock:
- Check the SkyHawk model number. Seagate’s current SkyHawk datasheet lists only CMR models, such as the ST8000VX010 and ST4000VX016. Older SKUs such as the ST4000VX013 and ST2000VX015 still turn up at resellers and are tracked as SMR by third-party CMR and SMR lists, so buy a model number that appears in the current datasheet.
- Check the Toshiba S300 part number. Toshiba’s S300 Pro page says the standard S300 uses SMR for setups where RAID isn’t required, and the S300 page doesn’t list recording tech per part, so confirm a part is CMR before you buy. The S300 Pro is CMR at 7200 RPM but was listed at about $780 for 8TB.
- Match a WD Purple 8TB listing to WD85PURZ. The current 8TB model in WD’s product brief was out of stock, and the in-stock WD82PURZ listing is an older SKU that isn’t in the brief, so we couldn’t confirm its recording tech.
- Read the seller line and condition. Most surveillance drive listings ship from third-party sellers, and one WD Purple Pro 12TB listing we found was used, not new.
SMR hurts more in a recorder than in a desktop. The camera writes never stop long enough for the drive to empty its CMR cache zone. Our HAMR vs UltraSMR guide covers why SMR drives fall apart during a ZFS resilver. If price is the problem, recertified NAS drives are a better route than an SMR surveillance disk.
Wire Frigate and UniFi Protect to the right storage
Frigate and UniFi Protect treat storage differently, and each one sets limits the drive has to fit. Frigate records to whatever disk you mount into the container. Its planning docs say hard drives give the best cost per gigabyte, that SSD wear is largely no longer a valid concern, and that local storage beats a network share. A Frigate box can use any of the four picks above. The right one depends on the camera count and on whether the disk holds anything else.
UniFi Protect is stricter because the console picks the storage type for you. Rack consoles and the UNVR Instant take 3.5-inch drives with the 7200 RPM CMR spec above. The CloudKey+ takes a 2.5-inch SATA SSD of at least 1TB requiring no more than 5V power, and Protect needs DRAM cache and 0.3 DWPD endurance on it. The UCG-Max and UCG-Fiber record to an NVMe SSD in an M.2 tray, limited to PCIe Gen3 x2, with the same DRAM and endurance requirement.
Ubiquiti’s camera limits matter as much as the drive. Its supported camera limits page puts the UNVR at 18 4K cameras, the UNVR Pro at 24 and the UDM Pro at 8.
The handoff from camera to disk is the same in both systems. The camera’s main stream bitrate decides how many gigabytes land each day, the retention setting decides how long they stay, and the workload rating decides how many of those streams one drive should carry. If you’re still choosing cameras, the bitrate settings in our Frigate NVR appliance build are the numbers to plug into the retention table.
Pair each recorder with its drive
This is the matrix we’d use when someone asks what to put in their box, with the reason each pairing holds:
| Recorder | Drive we’d fit | Why |
|---|---|---|
| Standalone 1 or 2 bay NVR, up to 6 cameras | WD Purple 4TB | Surveillance firmware, CMR, 180 TB/yr covers six 4K streams |
| Standalone NVR or Blue Iris PC, 7 to 16 cameras | Seagate SkyHawk AI 8TB | 550 TB/yr, five-year warranty; at 16 cameras 24/7 an 8TB disk holds about 7 days, so go bigger for longer retention |
| Frigate mini PC with one SATA bay | SkyHawk AI 8TB or WD Purple 4TB | Pick by camera count against the workload table |
| Frigate on a NAS or ZFS server that also stores files | WD Red Plus 10TB | 7200 RPM CMR, built for mixed NAS traffic up to 8 bays |
| UNVR, UNVR Pro, UDM Pro, UNVR Instant | Seagate IronWolf Pro 20TB or official UniFi HDD | Meets Ubiquiti’s 7200 RPM CMR requirement for RAID and ZFS |
| UniFi CloudKey+ | 1TB+ SATA SSD with DRAM, 0.3 DWPD | 2.5-inch bay, 5V power limit |
| UCG-Max or UCG-Fiber | NVMe SSD with DRAM, 0.3 DWPD | M.2 tray only, PCIe Gen3 x2 |
Two rows cover most readers: a Frigate or Blue Iris box with six cameras or fewer gets the WD Purple 4TB, and anything bigger gets the SkyHawk AI 8TB. The UniFi rows are fixed by Ubiquiti’s spec rather than by price, so a cheaper 5400 RPM surveillance disk there is a false saving. If your recorder can wait a few weeks, watch our Black Friday drive deals tracker before you buy.
