WD Purple is Western Digital's mainstream surveillance hard drive for everyday DVRs and NVRs: CMR recording, AllFrame firmware, a 180TB/year workload rating, 1 million hours MTBF and a 3-year limited warranty, in 1TB to 8TB. WD Purple Pro is the step up for AI-enabled recorders, video storage servers and VMS: 7200 RPM, AllFrame AI, OptiNAND, up to 550TB/year, 2 to 2.5 million hours MTBF, 32 AI streams, no drive-bay limit and a 5-year limited warranty, in 8TB to 22TB in our range.
Quick pick: a home or small-business NVR with up to 16 cameras recording continuously suits WD Purple (4TB to 8TB). A recorder running face, people or vehicle analytics, a VMS server, or a system with more than 16 bays suits WD Purple Pro.
ARC IP Networks is an authorised Western Digital reseller in Australia: genuine WD drives at competitive prices, with the full manufacturer's warranty, Australia-wide delivery and trade pricing. Browse every WD Purple and WD Purple Pro drive in our range.
WD Purple vs WD Purple Pro at a glance
Both ranges are 3.5-inch SATA CMR drives designed for recorders that write video 24 hours a day. The difference is the size of the job. WD positions WD Purple for mainstream video surveillance DVR and NVR systems, and WD Purple Pro for advanced AI-enabled recorders, video storage servers and video management systems (VMS).
| Feature | WD Purple | WD Purple Pro |
|---|---|---|
| Built for | Mainstream DVRs and NVRs | AI-enabled recorders, video storage servers, VMS |
| Capacities covered here | 1TB, 2TB, 3TB, 4TB, 6TB, 8TB | 8TB, 10TB, 12TB, 14TB, 22TB |
| Recording technology | CMR | CMR |
| Spindle speed | Not published by WD | 7200 RPM |
| Workload rating | 180TB/year | Up to 550TB/year |
| MTBF | 1 million hours | 2 million hours (8TB to 12TB), 2.5 million hours (14TB, 22TB) |
| Limited warranty | 3 years | 5 years |
| Drive bays supported | Up to 8 (1TB, 2TB), up to 16 (3TB and up) | No limit |
| Camera rating | Up to 64 single-stream HD cameras (WD publishes this for 6TB and above) | Up to 64 HD cameras plus 32 AI streams |
| Firmware | AllFrame | AllFrame AI |
| Other WD technologies | WDDA (per WD's AU product page) | OptiNAND, WDDA |
| RV sensors and tarnish-resistant parts | 3TB and up | Every capacity |
| Non-recoverable read errors | Less than 1 in 1014 bits | Less than 1 in 1015 bits |
| Cache | 64MB to 256MB | 256MB (8TB), 512MB (10TB to 22TB) |
| Load/unload cycles | 300,000 | 600,000 |
From Western Digital's WD Purple datasheet (November 2025), WD Purple Pro datasheet (July 2025) and WD's Australian product pages. MTBF figures are WD's, at a 40°C drive temperature; WD Purple Pro MTBF is a projected value.
WD Purple: the everyday CCTV drive
WD Purple is the drive most Australian installers fit to a home or small-business NVR. WD describes it as engineered for the "elevated heat fluctuations and equipment vibrations within NVR environments", and as built for 24/7 recording where an ordinary desktop drive is designed to run for short intervals. That matters in a recorder sitting in a hot comms cupboard, a garage or a ceiling space through an Australian summer.
Our WD Purple range covers 1TB (WD11PURZ), 2TB (WD23PURZ), 3TB in two versions (WD33PURZ with 256MB cache and WD34PURZ with 128MB), 4TB (WD44PURZ), 6TB (WD64PURZ) and 8TB (WD85PURZ). Every capacity carries the same 180TB/year workload rating (WD says up to three times that of desktop drives), 1 million hours MTBF and a 3-year limited warranty. WD's datasheet also lists RAID error recovery control "to help reduce failures in supported video recorders".
The smaller drives are a little more basic. The 1TB and 2TB models support recorders with up to 8 bays and have no RV sensors or tarnish-resistant components. From 3TB up, WD Purple supports up to 16 bays and adds both.
WD Purple Pro: built for AI recorders and VMS
WD Purple Pro is WD's enterprise-class surveillance drive. WD says modern cameras and AI-enabled recorders "send multiple streams of high-definition video, images, and metadata to storage at once", and Purple Pro is built to capture every one of them for real-time analysis. Think face recognition, people counting, vehicle analytics and long retention on a busy site: a shopping strip, a school, a council depot, a warehouse or a multi-site retail business.
Our Purple Pro range is 8TB (WD8002PURP), 10TB (WD102PURP), 12TB (WD122PURP), 14TB (WD142PURP) and 22TB (WD221PURP) (WD makes the family up to 26TB). Every model spins at 7200 RPM, is rated for up to 550TB/year (three times a mainstream surveillance drive, in WD's words), supports 32 AI streams and has no drive-bay limit, so it suits large recorders and storage servers. The warranty is 5 years.
The 8TB, 10TB and 12TB models are air-filled and rated at 2 million hours MTBF. The 14TB and 22TB are helium drives rated at 2.5 million hours, and they draw less power under load than the 10TB and 12TB (6.6 W and 6.9 W read/write against 9.1 W).
AllFrame, AllFrame AI, OptiNAND and WDDA explained
AllFrame (WD Purple)
WD says AllFrame "improves ATA streaming to help reduce frame loss and improve overall video playback". The datasheet describes it as optimised for the "write-intensive, low bit-rate, high stream-count workloads typical to mainstream surveillance applications". In plain terms, it is firmware tuned for many cameras writing at once, so playback has fewer gaps when you need the footage.
AllFrame AI (WD Purple Pro)
AllFrame AI goes further. WD says it "intelligently guides video, picture, and metadata streams to disk while mitigating dropped frames", helping keep complete, usable video data for accurate AI analytics. Analytics recorders write snapshots and metadata alongside the video, and this firmware is built for that mix.
OptiNAND (WD Purple Pro)
WD lists OptiNAND among the technologies on every WD Purple Pro capacity, and the 22TB label carries the OptiNAND badge. WD Purple does not list it.
WDDA: drive health alerts
Western Digital Device Analytics (WDDA) gives the recorder operational and diagnostic data from the drive, so the system can alert an administrator with recommended actions before a problem turns into lost footage. WD notes it needs a compatible video recorder or system. WD describes WDDA on its WD Purple product page as well as for WD Purple Pro.
Workload, MTBF and warranty: what the numbers mean
Workload rating is how much data WD expects the drive to transfer per year, reads and writes combined. A WD Purple is rated for 180TB/year and a WD Purple Pro for up to 550TB/year. Continuous recording plus AI analysis, frequent playback and exports all add to the total, so a busy analytics recorder uses up the WD Purple allowance much faster than a home NVR does.
MTBF (mean time between failures) is a population statistic, not a promise for one drive. WD rates WD Purple at 1 million hours with a 90TB/year workload and a 40°C drive temperature, and WD Purple Pro at 2 to 2.5 million hours with 220TB/year and 40°C. Both figures derate above those conditions, up to 65°C drive temperature. Good airflow around the recorder is the cheapest reliability upgrade you can make, especially in a hot Queensland or WA comms cupboard.
Warranty: WD Purple has a 3-year limited warranty and WD Purple Pro a 5-year limited warranty. For an installer quoting a maintenance contract, those two extra years on the drive are often what decides it.
Every WD Purple and WD Purple Pro model compared
Swipe the table sideways to compare all models →
| Model | Range | Capacity | Cache | Max bays | Workload | MTBF | Warranty | Read/write power |
|---|---|---|---|---|---|---|---|---|
| WD11PURZ | WD Purple | 1TB | 64MB | 8 | 180TB/yr | 1.0M h | 3 yrs | 3.8 W |
| WD23PURZ | WD Purple | 2TB | 64MB | 8 | 180TB/yr | 1.0M h | 3 yrs | 3.8 W |
| WD33PURZ | WD Purple | 3TB | 256MB | 16 | 180TB/yr | 1.0M h | 3 yrs | 4.7 W |
| WD34PURZ | WD Purple | 3TB | 128MB | 16 | 180TB/yr | 1.0M h | 3 yrs | 4.6 W |
| WD44PURZ | WD Purple | 4TB | 128MB | 16 | 180TB/yr | 1.0M h | 3 yrs | 4.6 W |
| WD64PURZ | WD Purple | 6TB | 256MB | 16 | 180TB/yr | 1.0M h | 3 yrs | 4.7 W |
| WD85PURZ | WD Purple | 8TB | 256MB | 16 | 180TB/yr | 1.0M h | 3 yrs | 5.3 W |
| WD8002PURP | WD Purple Pro | 8TB | 256MB | No limit | 550TB/yr | 2.0M h | 5 yrs | 7.3 W |
| WD102PURP | WD Purple Pro | 10TB | 512MB | No limit | 550TB/yr | 2.0M h | 5 yrs | 9.1 W |
| WD122PURP | WD Purple Pro | 12TB | 512MB | No limit | 550TB/yr | 2.0M h | 5 yrs | 9.1 W |
| WD142PURP | WD Purple Pro | 14TB | 512MB | No limit | 550TB/yr | 2.5M h | 5 yrs | 6.6 W |
| WD221PURP | WD Purple Pro | 22TB | 512MB | No limit | 550TB/yr | 2.5M h | 5 yrs | 6.9 W |
From the WD Purple (November 2025) and WD Purple Pro (July 2025) datasheets. Purple Pro workload is "up to" 550TB/year; Purple Pro MTBF is projected. Power is WD's average read/write figure at room temperature.
Which capacity for how many cameras?
WD rates both ranges using one reference camera: a single 1080p stream in H.265 at 25 fps and 3.2 Mbps. On that basis, WD publishes a rating of up to 64 single-stream HD cameras for WD Purple at 6TB and larger, and up to 64 HD cameras plus 32 AI streams for every WD Purple Pro. WD adds that results vary with resolution, codec, frame rate, software and settings. If you are running a big camera count on WD Purple, choose 6TB or 8TB rather than a smaller drive.
Capacity decides how many days you keep. At WD's reference bitrate, one camera recording continuously writes about 35GB a day. The table below applies that to each capacity. Treat it as a starting point: 4K cameras, higher frame rates and dual streams use far more, and motion-only recording uses less.
| Drive capacity | 4 cameras | 8 cameras | 16 cameras | 32 cameras |
|---|---|---|---|---|
| 2TB | about 14 days | about 7 days | about 3 days | under 3 days |
| 4TB | about 28 days | about 14 days | about 7 days | about 3 days |
| 6TB | about 43 days | about 21 days | about 10 days | about 5 days |
| 8TB | about 57 days | about 28 days | about 14 days | about 7 days |
| 12TB | about 86 days | about 43 days | about 21 days | about 10 days |
| 14TB | about 101 days | about 50 days | about 25 days | about 12 days |
| 22TB | about 159 days | about 79 days | about 39 days | about 19 days |
ARC IP Networks estimate: WD's reference stream (3.2 Mbps, 1080p, H.265, 25 fps) recorded 24/7, using the drive's full rated capacity. Usable capacity is a little lower once the recorder formats the drive.
For 4K cameras and other bitrates, use our security camera storage sizing guide.
Which drive for which Australian system?
| System | Our pick | Why |
|---|---|---|
| Home NVR, 4 to 8 cameras | WD Purple 2TB to 4TB | Weeks of continuous 1080p recording on a 1-bay recorder |
| Small shop, café or clinic, 8 to 16 cameras | WD Purple 6TB or 8TB | WD's 64-camera rating applies from 6TB, and 3TB-plus drives add RV sensors |
| Trades yard, farm shed or rural property | WD Purple 8TB | Longest retention in the WD Purple range for remote sites checked only now and then |
| Recorder running face, people or vehicle analytics | WD Purple Pro 8TB to 12TB | 32 AI streams, AllFrame AI and up to 550TB/year |
| Recorder or storage server with more than 16 bays | WD Purple Pro | No drive-bay limit (WD Purple stops at 16) |
| School, council, warehouse or retail chain on a VMS | WD Purple Pro 14TB or 22TB | Helium, 2.5 million hours MTBF, lower power per TB, 5-year warranty |
ARC IP Networks suggestions based on Western Digital's published ratings. Check your recorder's maximum drive size first.
The 8TB decision: WD85PURZ or WD8002PURP?
8TB is the one capacity in both ranges, so it is where the choice is most direct. The WD Purple 8TB (WD85PURZ) is rated for 180TB/year, 1 million hours MTBF, 16 bays and 3 years of warranty. The WD Purple Pro 8TB (WD8002PURP) adds 7200 RPM, AllFrame AI, OptiNAND, 32 AI streams, up to 550TB/year, 2 million hours MTBF, no bay limit and 5 years of warranty, and it draws more power (7.3 W against 5.3 W read/write).
If the recorder simply records cameras around the clock, the WD Purple 8TB does the job. If it runs analytics on many streams, or you want the longer warranty on a maintained site, pick the Purple Pro.
CMR on every model, and installing the drive
Every WD Purple and WD Purple Pro drive uses CMR (conventional magnetic recording). WD says CMR gives "predictable performance, better sustained write speeds, and reliability under continuous workloads", compared with SMR, which "can introduce latency during heavy writes". For a recorder that never stops writing, that is what you want.
Both ranges are standard 3.5-inch SATA drives (147 x 101.6 x 26.1 mm), so they fit the drive bays of typical Australian NVRs and DVRs. After fitting a new drive, the recorder has to initialise it before it records; our guide on how to install or format a hard drive in a Hikvision NVR walks through it. Choosing the recorder as well? See the best Hikvision NVR guide or our UniFi Protect NVR comparison.
WD Purple vs Seagate SkyHawk
Seagate SkyHawk is the other surveillance drive range Australian installers compare WD Purple against. Both brands build drives specifically for 24/7 recorders, so the right choice usually comes down to the capacity, workload rating and warranty for your system, and what your recorder maker has tested. ARC IP Networks stocks both WD Purple and Seagate SkyHawk, and we are preparing a separate side-by-side guide comparing the two brands model by model.
Why buy WD Purple from ARC IP Networks?
ARC IP Networks is an authorised Western Digital reseller in Australia: genuine WD drives at competitive prices, with the full manufacturer's warranty, Australia-wide delivery and trade pricing.
- The full WD Purple range from 1TB to 8TB and WD Purple Pro from 8TB to 22TB, listed by model number so you get exactly the drive you need.
- Western Digital's 3-year (WD Purple) or 5-year (WD Purple Pro) limited warranty on every drive.
- Trade pricing for CCTV installers, electricians and IT providers, and help matching drives to a recorder and camera count.
- A GST tax invoice on every order and delivery Australia-wide.
WD Purple and WD Purple Pro drives at ARC IP Networks
Open any drive for its full Western Digital specifications and to order online.
Entry-level CMR surveillance drive for small DVRs and NVRs with up to 8 bays. 3-year warranty.
CMR surveillance drive for home and small-office recorders with up to 8 bays. 3-year warranty.
3TB with 256MB cache, RV sensors and up to 16 bays. 3-year warranty.
3TB with 128MB cache, RV sensors and up to 16 bays. 3-year warranty.
Popular NVR size: 180TB/year workload, up to 16 bays, AllFrame. 3-year warranty.
Rated by WD for up to 64 single-stream HD cameras, 256MB cache. 3-year warranty.
The largest WD Purple: 64-camera rating, 256MB cache, up to 16 bays. 3-year warranty.
7200 RPM, AllFrame AI, 32 AI streams, up to 550TB/year. 5-year warranty.
512MB cache, OptiNAND, no bay limit, 2 million hours MTBF. 5-year warranty.
AI recorders and VMS: 32 AI streams, 512MB cache, 7200 RPM. 5-year warranty.
Helium, 2.5 million hours MTBF, 6.6 W read/write. 5-year warranty.
The largest in our range: helium, 2.5 million hours MTBF, no bay limit. 5-year warranty.
Common questions
Straight answers from the ARC IP Networks team. Last reviewed October 2026.
Both are CMR surveillance hard drives for 24/7 recording. WD Purple is built for mainstream DVRs and NVRs, with a 180TB/year workload rating, 1 million hours MTBF, up to 16 bays and a 3-year limited warranty. WD Purple Pro is built for AI-enabled recorders, video storage servers and VMS, with 7200 RPM, AllFrame AI, OptiNAND, 32 AI streams, up to 550TB/year, 2 to 2.5 million hours MTBF, no bay limit and a 5-year limited warranty.
If the recorder runs analytics such as face, people or vehicle detection across many cameras, WD Purple Pro is the better fit. Western Digital rates it for 32 AI streams and up to 550TB/year, and its AllFrame AI firmware is designed to write video, snapshots and metadata together. A recorder that only records cameras continuously is well served by WD Purple.
Western Digital rates WD Purple 6TB and larger for up to 64 single-stream HD cameras, based on 1080p H.265 at 25 fps and 3.2 Mbps per camera. WD Purple Pro is rated for up to 64 HD cameras plus 32 AI streams at every capacity. Real results depend on resolution, codec, frame rate and recorder settings.
At WD's reference stream of 3.2 Mbps per 1080p camera, eight cameras recording 24/7 write roughly 276GB a day. A WD Purple 4TB keeps about 14 days and a WD Purple 8TB about 28 days. 4K cameras use considerably more, so size up if your cameras record above 1080p.
CMR. Every WD Purple and WD Purple Pro model uses conventional magnetic recording, which Western Digital says gives predictable performance and better sustained write speeds under continuous recording than SMR.
WD Purple has a 3-year limited warranty from Western Digital and WD Purple Pro has a 5-year limited warranty. Bought from an authorised reseller in Australia, the drive carries the full manufacturer's warranty.
AllFrame is Western Digital's surveillance firmware on WD Purple. It improves ATA streaming to help reduce frame loss and improve video playback when many cameras record at once. WD Purple Pro uses AllFrame AI, which also guides image and metadata streams to disk for AI analytics.
Both are purpose-built surveillance drive ranges for 24/7 recorders, and neither is better for every system. Compare the capacity, workload rating and warranty you need, and check your recorder maker's compatibility list. ARC IP Networks stocks both WD Purple and Seagate SkyHawk.
ARC IP Networks is an authorised Western Digital reseller in Australia: genuine WD drives at competitive prices, with the full manufacturer's warranty, Australia-wide delivery and trade pricing. ARC IP Networks carries WD Purple from 1TB to 8TB and WD Purple Pro from 8TB to 22TB. Order online at arcip.com.au or call 1300 100 440.
Kitting out a CCTV job?
Tell us the recorder, how many cameras and how many days you need to keep. We will match WD Purple or WD Purple Pro drives to the job and quote them with trade pricing and Australia-wide delivery.
Related guides
- Western Digital Australia: every WD range explained
- How Much Storage Do You Need for Security Cameras? (2026 Sizing Guide)
- How to Install or Format a Hard Drive in a Hikvision NVR
- Best Hikvision NVR: Channels & Storage Guide (2026)
- UniFi Protect NVR Comparison 2026: Which Recorder Do You Need?
- Best Hard Drive for CCTV and NVRs in Australia: WD Purple vs Seagate SkyHawk
- CMR vs SMR Hard Drives Explained: What It Means for NAS and CCTV (Australia)