Scalability varies according to the type of system chosen, and must therefore be considered at the design stage of a video system.
Scalability steps:
A DVR system is usually supplied with 4, 9 or 16 camera inputs, therefore becomes scalable in steps of 4, 9 or 16. If a system includes 15 cameras, this is not an issue, but it becomes a problem if 17 cameras are needed. Adding one single camera would generate the need for an additional DVR. Network video systems are far more flexible, and can be scaled in steps of one camera at a time.
Number of cameras per recorder:
In a network video system, a PC server records and manages the video. The PC server can be selected according to the performance needed. Performance is often specified as number of frames per second, total for the system. If 30 fps is needed for each camera, one server may only record 25 cameras. If 2 fps is sufficient, 300 cameras can be managed by one server. This means that the performance of the system is used efficiently and can be optimized.
Size of system:
For larger installations, a network video system is easy to scale. When higher recording frame rates or longer recoding times are needed, more processing and/or memory capacity can be added to the PC server managing the video. Even more simply, another PC server can be added, located either at a central location, or at remote locations.
See also other System design considerations: