When purchasing a security system, you need to choose between DVR or NVR recorders. Both perform the same function, but differ in the type and type of camera used. When evaluating security systems, it is important to understand the difference between DVR and NVR. In this article, our security experts will break down the differences and elaborate on their strengths and weaknesses so that you can make informed decisions.
NVR and DVR – Basic Knowledge
The core of NVR and DVR is video recording. DVR stands for digital video recorder, while NVR stands for network video recorder. The difference between NVR and DVR is how they process video data. The DVR system processes video data in the recorder, while the NVR system encodes and processes video data at the camera, and then streams it to the NVR recorder for storage and remote viewing. Because DVR and NVR process video data in different ways, they need different types of cameras. Most NVRs are used for IP cameras, while DVRs are used for analog cameras. It is worth noting that DVR-based systems are wired security systems, while NVR systems can be wired or wireless systems.
DVR Security System – Advantages and Disadvantages
Advances in simulated high resolution over the past five years have reduced the resolution gap between the two systems. You may notice that DVR-based security systems are less expensive than NVR systems. Lower price point is an attractive advantage of DVR system, but what trade-offs? To answer this question, we need to decompose each component of the DVR system.
DVR systems must use analog security cameras, better known as CCTV cameras. Using DVR system can save most of the cost because of the camera. Although you can mix and match cameras in a home security system, you have less flexibility in the type of cameras you can use in a DVR system.
In DVR system, the analog camera transmits the analog signal to the recorder, and then the recorder processes the image. Compared with NVR system, the advantage of this system is to reduce the complexity of the camera.
Cable-coaxial BNC cable
The camera is connected to the DVR recorder via a coaxial BNC cable. Although the use of coaxial cables does not seem important, it does have some limitations:
Since the coaxial cable can’t power the camera, there are actually two cables contained in one cable and video cable. Each end of the cable is separated to provide a separate function. Therefore, you need to install a DVR recorder near the power outlet.
The size and stiffness of coaxial cables can make installation more challenging. The coaxial cable has a wider diameter than the Ethernet cable used in the NVR system, which makes it more difficult to run the cable in a narrow space. Coaxial cables are also often harder, making the problem more complex.
However, if your property has an existing coaxial connection to the previous security system, you can connect the new system with the same cable.
Standard coaxial cables do not support audio. Variants of RCA connections need to be added, but even if these DVRs have a limited number of audio input ports, only a few cameras can record audio.
The image quality on the coaxial cable begins to decrease after about 300 feet/90 meters, which may limit your ability to extend your security presence outward. Lower quality cables can result in loss of signals over shorter distances.
DVR recorders rely on hardware chipsets called AD encoders, which process raw data from the camera to clear video recordings. DVR systems also have different requirements for recorders. Specifically, in a DVR system, the user must connect each camera directly to the recorder. In contrast, the NVR system only requires each camera to connect to the same network. In addition, in DVR system, the recorder does not supply power to the camera. Each camera connection requires a distributor that provides power to make the camera work properly.
In terms of camera type and installation options, the flexibility of DVR security system is lower than that of NVR security system. NVR-based systems can integrate wired and wireless security cameras, while DVR systems can only use wired security cameras. DVR system installation solutions are also not very flexible, because it is more difficult to route coaxial cables under tight conditions, and each camera needs a power outlet.
Image and audio quality
As we discussed, in a DVR system, the camera transmits analog video directly to the VCR through a coaxial cable and processes images at the VCR level. Compared with NVR system, analog signals lead to lower quality images. The coaxial cable itself does not transmit audio signals, and the DVR recorder usually has a limited number of audio input ports.
NVR Security System – Advantages and Disadvantages
NVR security camera system uses the latest technology to provide enhanced and functional security system. Also known as POE security camera system, NVR-based system is more flexible and complex than DVR system.
Camera Type – IP Camera
Because NVR systems process video data on cameras rather than video recorders, the cameras in NVR systems are more powerful than those in DVR systems. NVR systems use IP cameras, which are independent image capture devices. Each IP camera has a chipset that processes video data and then transmits it to the VCR. Unlike analog cameras, IP cameras can usually record and send audio and video. More powerful hardware on IP cameras can also improve intelligent functions and video analysis, such as face recognition.
Like DVR systems, NVR systems connect cameras to video recorders. But how they connect cameras to VCRs is completely different. NVR systems use standard Ethernet cables (such as CAT5e and cat6) to transmit data. Because of its many advantages over coaxial cables, professional installers prefer Ethernet cables:
The Ethernet cable uses PoE to power the camera, which means that your camera needs to run a cable to capture the video, audio and power of the camera, so there is no need for a disruptor like a DVR system.
Ethernet cables tend to be easier to wire and terminate because they are thinner and have smaller connectors that reduce drilling.
Ethernet is cheaper and more accessible than coaxial cable, making cable replacement or system expansion more accessible and affordable. Many modern households and businesses are building wired Ethernet to make installation easier.
Another advantage of the Ethernet cable is that each camera on the system can transmit audio, because Ethernet can send audio data locally.
The cable does not need to run between each camera and video recorder. They need to be on the same wireless network. Since no more cables are needed, the installation is simpler and cleaner.
Although the maximum Ethernet cable length (328 feet or 100 meters) is relatively short, network switches can be used to extend the total distance without affecting image quality.
Unlike DVR systems, VCRs in NVR systems do not process video data. This step is completed before the camera is transmitted. NVR recorders are only used to store and view material.
NVR systems are inherently more flexible, because security cameras do not necessarily have to be physically connected directly to the VCR. Instead, IP cameras need only be on the same network. Therefore, you can use cameras all over the world on the same network connected to NVR, and then you can think of them as an integrated system.
Image and audio quality
Because NVR receives pure digital signals from the camera, the video quality is better than that of DVR with the same resolution. In addition, all microphone-equipped cameras can record audio to NVR due to the transmission of audio over Ethernet cables.
Summary – DVR and NVR systems
Both systems record video data and are reliable. Although DVR systems used to lag behind comparable NVR systems in video quality, today the gap has narrowed significantly. The differences between DVR and NVR systems come down to cost, data transmission mode and camera type. NVR systems tend to have better image quality, easier installation, greater flexibility, and native audio support for each camera with a microphone. However, NVR systems are often much more expensive than similar DVR systems, which is an important consideration for budget-conscious consumers. For those looking for relatively simple security systems, DVR systems are probably enough, especially if your assets are already connected to coaxial cables from existing security systems. If you need top-level, very flexible solutions, NVR-based systems will be the best. At the end of the day, the determinants will be based on the specific security needs of your property.