CCTV Hard Drive: Workload Tiers, Sizes and Amazon.co.uk Prices

Which CCTV hard drive: three workload tiers on the makers' sheets

Surveillance drives are graded by workload rather than by speed. WD defines that rating as terabytes transferred, scaled to a full year of 8,760 hours, so a drive that records day and night is measured against everything it moves in that year.

Seagate states the gap at the top directly: it rates SkyHawk AI at more than three times a standard surveillance drive, and says it handles video analysis and recording at the same time. Its October 2017 SkyHawk sheet calls the 180TB figure a low-transaction workload at a 20 per cent duty cycle, which places the standard tier at steady recording.

The middle rung is easy to miss because WD splits its standard line by part number. At 8TB, WD82PURZ sits at 360TB a year and WD81PURZ at 180TB, so a brand name and a capacity on a listing do not tell you which rating you are buying. WD Purple sets out every model.

CCTV hard drive price on Amazon.co.uk

In all, the table draws on 53 listings in stock. The table shows 24 listings, sorted by price per terabyte; the lowest is £25.76/TB. Every price is pounds sterling inc VAT, and each row is marked new or used. WD Purple, Purple Pro, SkyHawk, SkyHawk AI and Toshiba S300 listings all land here, so the tiers sit side by side: check the family in the title before you compare two prices.

The Recording column names CMR or SMR only where a maker document covers that part number or its family. A CMR in an Amazon title is the seller's claim, and we do not repeat it as ours.

CCTV hard drive 1TB, 2TB, 4TB, 6TB or 8TB: picking a size

Size follows from three numbers: how many cameras, how much each one streams, and how many days you keep footage. WD's camera figures assume one stream per camera at 3.2Mbps, which it describes as 1080p, H.265 at 25 fps, and WD says real results vary with resolution, format, frame rate and software.

At that reference rate one camera recording all day writes about 34.6 GB, by our arithmetic, so each terabyte holds roughly 29 camera-days. WD counts a terabyte as one trillion bytes, the same decimal unit printed on the drive's label, so these figures compare directly with the capacities in the table.

• 1TB: about four weeks for one camera at the reference rate.
• 2TB: about four weeks for two cameras, or two weeks for four.
• 4TB: about four weeks for four cameras.
• 6TB: about four weeks for six cameras, or about three weeks for eight.
• 8TB: about four weeks for eight cameras, or about two weeks for sixteen.

Treat those as planning figures. Axis, the camera maker, says that with variable bitrate the main drawback is that storage needs may be unpredictable. The CCTV storage calculator takes your own bitrate, hours per day and days kept.

Workload is the second check. Four cameras at the reference rate, recording all day, transfer about 50TB a year by the same arithmetic, well inside the 180TB standard tier. Somewhere around fifteen such cameras on one drive the total passes 180TB a year. The next rungs are WD's AllFrame AI models at 360TB, which cover up to about 28 such cameras, and then the 550TB class.

CCTV hard drive recorder fit and replacement

Before you replace a drive, check what the recorder maker says. Hikvision publishes one such document, its drive list, edition v20260515, and three points in it matter to any buyer:

• IoT-model drives: Hikvision says they are not compatible with its NVRs and DVRs because they are encrypted.
• DM SMR drives: Hikvision allows them normal storage only, so they are out for RAID, Dual-VCA data storage and custom log storage.
• The DM SMR table is not one brand's problem: it names 11 Seagate part numbers, among them ST4000VX013 and ST2000VX015, six WD numbers such as WD41PURX-78, and four Toshiba DT02 models, so a brand or family name alone does not settle the question.

Hikvision organises that list by recorder series, so match your recorder's series as well as the drive. Hikvision hard drive sets the list's entries beside Amazon.co.uk stock. For the recorder type, NVR hard drive deals with network recorders running AI analytics, and DVR hard drive covers the standard 180TB-a-year tier on its own.

For other recorder brands we have not found a compatibility document in our sources. Check the recorder's manual for the largest drive it accepts and the interface it expects before you order.

Warranty years printed on a data sheet are the maker's promise for that model. An individual Amazon.co.uk offer, and a used one especially, can come with different terms, so the listing itself is what to read. The brand pages hold the full sheet figures: WD Purple Pro, Seagate SkyHawk and WD Purple 8TB.