Video recording solutions in the IP surveillance market come in two varieties, Network Video Recorders (NVR) and PC-based systems. Both these recording solutions provide a storage facility for the content captured by surveillance cameras; and take care of the functions of managing the cameras, recording content, viewing content, and archiving content. The differences between the two lie in how they operate and the features they provide.
On a scale of 1 to 5, with 1 being ‘Poor’ and 5 being ‘Excellent’, the table below shows the various features of an NVR as compared to a PC-based recording solution.
Size
The stand-alone NVR comes with all the components in a single box, and is compact, while a PC-based system is built around a general-purpose desktop/notebook and comes with a separate CPU, keyboard, a USB mouse and monitor. Thus, a stand-alone NVR occupies less shelf-space while performing similar functions.
Storage
Although NVRs have ample internal recording and storing space, the PC-based systems offer as much as seven times more storage, when compared to an NVR. This advantage is, however, addressed by NVRs, through the provision for external storage options (USB storage devices, eSATA devices, Firewire storage devices, NAS appliances, etc.)
Stability
The NVR is extremely stable and reliable since it contains fewer components. The software is often written in basic machine code or Linux code and is designed to run only one application. This tends to make the NVR more stable when compared to a PC-based system running a Windows application.
Boot Time
The NVR runs an embedded operating system as compared to a PC-based system, which needs to run an application under the Windows OS before it begins recording. This means that the NVR will start faster as compared to the PC-based system; which will take longer to load.
Security
Both NVRs and PC-based systems can connect directly to the network (LAN/WAN). The NVR is optimised for video recording and viewing, and is stripped off software components and modules that do not assist in these functions. A PC-based system is dedicated as well, but on account of the non-optimised nature of the OS and attendant applications, is open to the standard problems a user may encounter in a network; like virus attacks, hacking, etc.
Performance
On account of the function-specific processors that NVRs are typically built around, NVRs offer a performance advantage over PC-based systems. PCs use the CPU for video compression/decompression, viewing and recording content, and managing cameras; while an NVR usually has one or more DSPs for video compression/decompression, and a CPU (albeit less powerful than its PC-based system counterpart) for the other functions. Obviously, a PC-based system with a very powerful CPU and oodles of RAM can match the performance of an NVR; but, such a system is going to be more expensive.
Scalability
An NVR is designed to offer optimal performance for a set number of cameras, and is normally less scalable than a PC-based system. This makes the unit suitable for smaller systems where the number of cameras stays within the limits of an NVR’s designed capacity.
