4-Camera vs 8-Camera NVR Storage
Doubling camera count roughly doubles video storage when bitrate, hours and retention stay the same. The practical difference is that eight-camera systems cross common single-drive capacity thresholds much faster.
| 30-day continuous recording | 4 cameras | 8 cameras |
|---|---|---|
| 2 Mbps each | 2.59 TB raw | 5.18 TB raw |
| 4 Mbps each | 5.18 TB raw | 10.37 TB raw |
| 6 Mbps each | 7.78 TB raw | 15.55 TB raw |
| 8 Mbps each | 10.37 TB raw | 20.74 TB raw |
Why eight cameras change recorder planning
With four cameras, a single large surveillance drive may cover many home-retention targets. At eight 4K cameras, 30-day continuous retention can require multiple drives, a larger recorder chassis or a NAS depending on actual bitrate and redundancy.
Storage is not the only doubling effect
An eight-camera system also increases PoE power draw, switch/NVR port requirements, aggregate network traffic and UPS load. The jump from four to eight cameras should be treated as a system-capacity decision, not just four more camera purchases.
Motion recording changes the curve
Motion-only recording can reduce storage materially, but duty cycle varies by scene. Busy streets, trees, rain and insects can erase much of the expected savings.
Use the Storage Cost Calculator for drive count and cost, or the NVR Hard Drive Calculator for capacity-only planning.