Choosing a hard drive for surveillance recording

Check your recorder before choosing a capacity

Find the exact DVR or NVR model, firmware version, supported drive interface and maximum supported capacity per bay. Check its drive compatibility list for the full manufacturer model number. Two 3.5-inch drives with the same capacity are not necessarily interchangeable: a SATA recorder cannot operate a SAS drive. Also check the physical mounting and power requirements. A desktop or NAS label alone does not establish that a drive is supported by your recorder.

Calculate recording days from bitrate

For continuous recording, daily storage in decimal GB is approximately total camera bitrate in Mb/s × 10.8. Retention days are nominal capacity in TB × 1,000 ÷ daily GB. For example, eight cameras recording at 4 Mb/s each produce about 345.6 GB per day. A 4TB drive therefore holds about 11.6 days before filesystem overhead and reserved space. If you reserve 20% of capacity, the planning estimate becomes about 9.3 days. These are arithmetic estimates, not recorder benchmarks. Variable bitrate, audio, codec settings, motion recording and the recorder's storage policy change the result.

Camera support and recording duration are different limits

A manufacturer camera-count rating describes a supported workload under stated conditions; it does not mean that the smallest capacity can store weeks of footage from that many cameras. Read the exact model's camera, transfer and workload specifications together. Leave headroom for playback, footage export and simultaneous recording. Check the recorder's own incoming-bandwidth limit too: buying a higher-rated drive does not increase that limit.

Example: ST1000VX003 is a specific +Rescue model

Seagate's Surveillance HDD datasheet identifies ST1000VX003 as the 1TB +Rescue variant. It lists SATA 6 Gb/s, 64MB cache, up to 180 MB/s sustained transfer, up to 64 cameras and no rotational-vibration sensor for that model. Published average operating and idle power are 5.6W and 4W. The catalog links to the manufacturer document and the exact Amazon US ASIN. An old +Rescue package designation does not establish that recovery-service coverage is active for a used drive or a purchase today; verify eligibility for the serial number and purchase date.

For multi-drive recorders, compare more than price per TB

Look for the model's documented drive-bay support and vibration-sensor specification, and compare power figures measured under equivalent manufacturer conditions. If you buy renewed hardware, establish who provides the warranty and returns, and test the drive before relying on it. A larger cache does not establish a reliability advantage. A workload rating is not an expected lifespan. If footage is important, decide which recordings need a separate backup or export; recording to a single drive is not a backup strategy.

Build a shortlist of exact models

Choose the required capacity from your retention estimate, filter the catalog to surveillance models, and check each part number against your recorder documentation. Use the comparison pages to check interface, sustained transfer, power and documented features side by side. Open the direct Amazon US listing only after choosing a model, then confirm the selected capacity, part number, condition and seller terms. A verified ASIN can remain valid while the product is unavailable; a product link is not an in-stock claim.

Quick Decision Guide

Frequently Asked Questions

Sources

• Seagate Surveillance HDD datasheet, DS1679-16, model specifications on page 2