Do You Actually Need a Surveillance Drive? WD Purple and Skyhawk, Priced (August 2026)
Someone asked the question properly on r/DataHoarder and then explained exactly why they could not find an answer:
“Does it really matter whether you get Green, Red, Purple, Gold, Skyhawk, BarraCuda, Ironwolf, Exos or any other flavor of drives? … to me a lot about this doesn’t seem very concrete and feels more like marketing. … I honestly couldn’t find much information about this besides reviewers repeating what the press release from Seagate/WD reads.”
- u/Internal-Editor89, r/DataHoarder
That last sentence is the whole problem. Every buying guide on this topic restates the manufacturer’s page. Nobody puts a price on it.
I track every drive listing on Amazon.com and recompute price per terabyte daily, so I can. All prices below are internal 3.5” SATA drives, measured 8 August 2026, cheapest live listing in each family at each capacity. SATA only on purpose, and there is a whole section below explaining why that filter matters more than it sounds.
First, the technical question, because the price only means something once it is settled
The threads contain a real dispute with a resolvable answer, and it gets resolved the same way every time. Someone states the scary version:
“Purples are mostly 5400RPM models optimized for streaming data that cares more about an uninterrupted data stream than for perfect writes. … More importantly though, they will outright ignore minor write errors on purpose in order to avoid dropped frames. This generally makes them a terrible choice for a RAID array of any sort.”
- u/Drenlin, same thread
And someone more specific corrects it:
“Purples will only do this if you use them in a DVR/CCTV system that supports those specific ATA extensions. Purples will not have write errors when used in a desktop PC or standard NAS, since they don’t recognize those ATA extensions. They will operate like any other drive.”
- u/The_Game_Player, same thread
The same exchange happens in a different thread, almost word for word:
“Not true. NVR HDD’s will operate as a normal hard drive with same ECC as any other. They just contain an added SATA/ATA/ATAPI feature set that is activated by the NVR to skip bad or questionable sectors when recording instead of trying to re-read or re-write constantly, causing a gap in time in the recording.”
- u/HTWingNut, r/DataHoarder
“Unless you leverage the streaming feature set, they shouldn’t transfer data any less accurately than any other drive.”
- u/MWink64, same thread
There is a loud dissent, and I am including it because I want you to see it rather than take my summary:
“NO! Do not listen to these people. Purples are not made for integrity, they are made for constant writes on the cheap. If you have nothing else, use as temp, but do not be surprised by corruption.”
- u/Organic-Efficiency47, r/DataHoarder
I cannot adjudicate that from listing data and I am not going to pretend to. What I can say is that the specific claim (an ATA streaming command set the recorder has to activate) is testable and consistent across the people who state it precisely, while the vaguer claim is stated without a mechanism. The people who actually run software NVRs are the most dismissive of all, which is the closest thing to field evidence in the whole harvest:
“fun fact, purple drives don’t have any benefit in a blueiris server… I have an 18tb in mine, so I do know :D”
- u/squirrelslikenuts, r/BlueIris
“You don’t need purple drives, they don’t provide any special capabilities on a Windows PC, just get NAS drives or even a Blue drive instead.”
- u/Hot_Cheesecake_905, same thread
So the question that decides your purchase is not “which drive”
It is what is doing the recording, and this distinction is buried three replies deep in every thread instead of being the first thing anyone asks.
A hardware DVR or NVR box (Hikvision, Dahua, Lorex, Reolink, a UNVR) may genuinely speak the streaming feature set. If yours does, the surveillance drive is doing something, and the premium below is buying you a real behaviour: dropped frames instead of retry stalls.
A software NVR on a PC (Blue Iris, Frigate, Shinobi, anything running on Windows or Linux) does not. The drive is a normal SATA drive with a purple sticker. Everything you pay above the equivalent NAS or enterprise drive is buying a label.
Work out which one you are before reading the tables. It changes the answer completely and nothing else on this page does.
What each family actually costs
Cheapest live SATA listing per family, per capacity, per condition, on Amazon.com, 8 August 2026.
8 TB
| Family | New $/TB | New price | Used $/TB | Used price |
|---|---|---|---|---|
| WD Purple (surveillance) | $51.74 | $413.95 | $37.50 | $299.99 |
| Seagate Skyhawk (surveillance) | $61.84 | $494.75 | $36.25 | $289.99 |
| WD Red Plus (NAS) | $44.37 | $354.99 | $36.94 | $295.49 |
| Seagate IronWolf (NAS) | $56.81 | $454.45 | $35.27 | $282.14 |
| Seagate Exos (enterprise) | $43.99 | $351.96 | $33.12 | $265.00 |
| WD Gold (enterprise) | $68.62 | $549.00 | $26.12 | $209.00 |
| Seagate BarraCuda (consumer) | $33.42 | $267.39 | $28.83 | $230.62 |
12 TB
| Family | New $/TB | New price | Used $/TB | Used price |
|---|---|---|---|---|
| WD Purple Pro (surveillance) | $47.08 | $564.99 | $25.54 | $306.53 |
| Seagate Skyhawk (surveillance) | $47.89 | $574.65 | n/a | |
| WD Red Plus (NAS) | $38.33 | $459.99 | $35.44 | $425.25 |
| Seagate IronWolf Pro (NAS) | $45.00 | $539.99 | $29.17 | $349.99 |
| Seagate Exos (enterprise) | $40.00 | $479.99 | $25.00 | $299.99 |
| WD Gold (enterprise) | $48.50 | $582.00 | $48.50 | $582.00 |
| Seagate BarraCuda Pro (consumer) | $40.95 | $491.45 | $41.58 | $499.00 |
16 TB
| Family | New $/TB | New price | Used $/TB | Used price |
|---|---|---|---|---|
| Seagate Skyhawk AI (surveillance) | $43.09 | $689.41 | $34.31 | $549.00 |
| WD Red Pro (NAS) | $44.06 | $704.99 | $38.29 | $612.69 |
| Seagate IronWolf (NAS) | $43.12 | $690.00 | $28.12 | $449.99 |
| Seagate Exos (enterprise) | $46.53 | $744.45 | $31.19 | $499.00 |
| Seagate BarraCuda (consumer) | $31.25 | $499.99 | n/a |
On new stock, the premium is real and it is large
- 8 TB: a new WD Purple is 55% more per terabyte than a new BarraCuda. $51.74 against $33.42.
- 16 TB: a new Skyhawk AI is 38% more than a new BarraCuda. $43.09 against $31.25.
- 12 TB: a Purple Pro is 23% more than WD’s own NAS drive, the Red Plus. $47.08 against $38.33.
- The two surveillance families do not even agree with each other. At 8 TB the cheapest new Skyhawk AI is $61.84/TB while the cheapest new Purple is $51.74, a 20% spread inside the same product category.
If you are running Blue Iris on a PC, that is the whole cost of the sticker.
On the used shelf, it inverts completely
This is the part I did not expect, and I have not seen it anywhere else.
Look at the 12 TB used column again. A used WD Purple Pro is $25.54/TB. Out of all 44 used 12 TB SATA listings I track, only two are cheaper: an HPE midline pull at $24.92 and a recertified Exos at $25.00. The Purple beats every NAS drive on the shelf, including a used IronWolf Pro ($29.17), a used Red Plus ($35.44) and a used BarraCuda Pro ($41.58).
The reason is not mysterious. Surveillance drives get pulled out of commercial installations in volume when a site is refitted, and the recertified market does not price a purple sticker at a premium the way retail does. So the label that costs you 23% extra new is worth nothing on resale, which is bad for the person who bought it new and very good for you.
Practical upshot: if you want a surveillance drive, buy it used. The 12 TB Purple Pro at $306.53 is a genuinely good buy on price alone, whatever you think of the streaming feature set, because you are getting it for less than the NAS drives it competes with.
And at 8 TB the cheapest drive on the whole board is a used WD Gold at $209.00, $26.12/TB, which is an enterprise drive at half the price per terabyte of a new Purple. That is the comparison the manufacturer pages will never draw for you.
If you want the general version of this argument, refurbished and used drives covers what to check before you pay, and the warranty point below matters more than usual here.
Two traps that are live today
Both of these will bite anyone who takes “just buy cheap refurb enterprise” at face value.
1. SAS masquerading as a bargain. The cheapest 16 TB “Exos” on Amazon.com right now is $25.56/TB, $409.00, and it is SAS 12Gb/s. It will not plug into a DVR, and it will not plug into a normal motherboard without a host bus adapter. Filter that family to SATA and the cheapest Exos becomes $31.19/TB, so the apparent saving of $5.63/TB is not a deal, it is a different interface.
The detail that makes this worth checking rather than just avoiding: there is a Toshiba MG08ACA16TE at exactly the same $409.00 and $25.56/TB, and it is SATA. The cheap price was never the SAS drive’s doing. Reading the interface field would have got you the same money and a drive you can actually plug in.
This is not a rare edge case. Across the drives I track, SAS listings cluster hard at the cheap end of the price-per-TB sort precisely because most buyers cannot use them.
2. SMR wearing an enterprise badge. The cheapest new 8 TB SATA drive in the Exos family is the Seagate Exos 5E8, ST8000AS0003, at $43.99/TB. Its own title says 512e SMR 256MB Cache 5400RPM. It is an SMR drive, and it is 5400 RPM, inside the product family everyone recommends as the safe enterprise choice.
SMR under continuous 24/7 recording is the single worst outcome anything on this page could lead you into. Shingled drives rewrite overlapping tracks, so sustained writes eventually fall off a cliff, and continuous recording is nothing but sustained writes. CMR vs SMR covers how to check a specific model.
Both traps have the same fix: read the model number, not the family name.
The honest argument for paying more
There is a real one, and it is not the streaming feature set. It is duty cycle, and it comes from the people who have watched consumer drives die:
“I’ve had a pretty bad experience trying to run barracudas and blues 24/7 in a nas. they all die within like 2-3 years. … Took me a while to realise that my box of dead drives was 90% Barracudas, while I have 4 ex-enterprise Toshibas from 2012 were still chugging.”
- u/aew3, r/DataHoarder
Surveillance is the one home workload that genuinely is write-heavy, continuously, forever. Here is the arithmetic nobody in these threads runs:
| Bitrate per camera | Per day | Per year |
|---|---|---|
| 2 Mbps | 21.6 GB | 7.9 TB |
| 4 Mbps | 43.2 GB | 15.8 TB |
| 8 Mbps | 86.4 GB | 31.5 TB |
Which scales the way you would fear:
| System | Continuous write volume |
|---|---|
| 4 cameras at 4 Mbps | 63 TB/year |
| 8 cameras at 4 Mbps | 126 TB/year |
| 16 cameras at 4 Mbps | 252 TB/year |
That is a real workload and it is a fair reason to want a drive built for continuous operation. What I am not going to do is quote you manufacturer workload ratings, because I have not checked a single datasheet today. Numbers get passed around these threads (180 TB/yr for this family, 550 TB/yr for that one) and every one of them is hearsay until someone opens the PDF. I would rather give you the arithmetic and let you check your own drive’s rating than print a number I have not verified.
The important qualifier: this argument favours drives rated for 24/7 operation, which includes NAS and enterprise drives, not surveillance drives specifically. A used Exos or IronWolf Pro satisfies it at a lower price per terabyte than a new Purple. And it collapses entirely if you record on motion rather than continuously, which most home systems do and which nobody separates out.
Warranty, which is the question that got asked and never answered
Someone put it precisely and got no replies at all:
“Seagate Exos has a 5 year warranty, and the Skyhawk has 3. Both are CMR incase someone is wondering. … Exos seems the cheapest model with 5 year warranty, but Seagate seems to have some advanced ImagePerfect firmware for NVR. I am inclined more towards the Exos. Am I missing something here?”
- u/blackpropagation, r/DataHoarder
I can answer half of it from listing data, and I want to be careful about which half.
What I can see is what each listing states, not what the manufacturer offers. Across the SATA drives I track: 30 of 63 Purple listings state a warranty at all, 18 of 44 Skyhawk, 45 of 68 Exos. So more than half of surveillance-drive listings state no warranty term whatsoever, and Exos listings are the most likely of any family to state one.
Treat a blank as zero, always. That is not a technicality: on used stock a stated long warranty is routinely cheaper per terabyte than no warranty at all, so there is no reason to accept a blank.
As for the original question, the answer that nobody gave: on today’s prices the Exos is the better buy at 12 TB used ($25.00/TB) and the IronWolf Pro at 16 TB used ($28.12/TB), and the ImagePerfect firmware only matters if a hardware recorder is asking for it.
The thing no buying guide mentions
Noise. It comes up constantly and unprompted:
“CMR/SMR makes more a difference than the drive colors. SMR is fine for non-critical systems. One thing I have noticed about Purples though (noisy af, holy shit)”
- u/wh33t, r/DataHoarder
There is a whole thread about Purple Pro grind. For a recorder that lives in a cupboard this is irrelevant. For one that lives in a living room or a home office it may matter more to you than $5/TB. I have not measured any of this and cannot rank the families on it. I mention it only because you will not find it in a spec comparison and you will notice it on day one.
What I would actually buy
I run Unraid rather than a camera system, so take this as reasoning from the numbers rather than from my own NVR.
Software NVR (Blue Iris, Frigate) on a PC: skip the surveillance label entirely. Buy on price per terabyte, insist on CMR, insist on SATA, and prefer a stated warranty. Today that points at a used IronWolf Pro 16 TB at $449.99, $28.12/TB, or the used Exos at 12 TB.
Hardware DVR or NVR box: the streaming feature set may actually be doing something, so a surveillance drive is defensible. Buy it used, where it costs less than the NAS drives rather than more. The 12 TB Purple Pro at $25.54/TB is the standout.
Either way: check the model number for SMR, check the interface for SAS, and treat a blank warranty as zero. Those three checks matter more than the colour of the sticker.
Bottom line
As of 8 August 2026, on Amazon.com, internal 3.5” SATA drives:
- The surveillance feature set is an ATA streaming command set that the recorder activates. Hardware DVR, it may matter. Software NVR on a PC, it provably does not.
- New surveillance drives cost 23% to 55% more per TB than the alternatives at the same capacity.
- Used surveillance drives are the opposite. A 12 TB Purple Pro at $25.54/TB is third cheapest of the 44 used 12 TB listings I track, ahead of every NAS drive. The sticker that costs you extra new is worth nothing on resale.
- The cheapest 8 TB drive of any kind is a used WD Gold at $26.12/TB, half a new Purple per terabyte, with an enterprise pedigree.
- Two live traps: the cheapest 16 TB Exos is SAS, and the cheapest new 8 TB Exos is SMR. Read the model number.
- The write volume is real (126 TB/year for eight cameras at 4 Mbps), and it argues for a 24/7-rated drive rather than a surveillance-branded one specifically.
- More than half of surveillance-drive listings state no warranty at all. Treat blank as zero.
For live prices, best surveillance drives tracks this category and cheapest HDD per TB ranks everything. To judge a listing you already have open, the good price per TB benchmark has percentile bands by capacity. For the used market specifically, what to check before you pay, and for the SMR question, CMR vs SMR.
Prices in this article were measured from live Amazon.com listings on 8 August 2026 and cover internal 3.5” SATA hard drives only, cheapest listing per family per capacity per condition. Manufacturer workload ratings are deliberately not quoted because I have not verified them against current datasheets. Reddit quotes are from public threads, linked at each quote. HDDHunt earns a commission on purchases made through links on this site, at no extra cost to you. See the affiliate disclosure.