The difference between NVR and DVR

When you research for a surveillance security system you’ll definitely come across two terms: NVR and DVR. This article will explain what’s the difference between a NVR and a DVR, which is better, or more importantly, which system is better suited for your needs. Both types of systems pretty much provide the same thing – a video recording of an observed area – but each system goes about it in a different way. The two main differences between NVR (Network Video Recorder) and DVR (Digital Video Recorder) surveillance systems are the type of cameras used and the way the camera and recorder communicate with each other.

What’s the NVR?

A network video recorder (NVR) works with either wired or wireless IP cameras that connect to a router/switch or directly on the built-in PoE switch inside the NVR itself. It’s through the network that the IP (network) cameras communicate with the NVR. IP cameras also have built-in hardware and software capabilities to process the video signal from analog to digital, meaning the initial processing is done by the camera itself, hence less work for the NVR and the system gets more efficient.

A typical NVR with built-in PoE switch. Notice the ports for the IP cameras.

NVR systems also can connect to a computer or storage device via the Internet or a local area network (LAN). This reduces the cost of running wires and provides more options of where to place the cameras. Let’s say you have a five floors hotel, each floor needs 10 camera: you can connect all the cameras of the floor to a single switch and then the switch through cats5/cat6 goes to the next floor, and everything comes together to the NVR. You don’t have to bring each camera individually to the NVR.

What’s the DVR?

A digital video recorder (DVR) works with wired, analog or digital cameras that connect directly to the DVR. You can identify these cameras easily by their bnc connector on the pigtail. The DVR basically converts the video feed from the camera into a digital, compressed format, which can be stored on a memory card, hard drive, or computer. Since DVRs are made to work with analog cameras that are connected through coaxial cable, upgrading an existing CCTV system can be easy because the coaxial wiring is already in place. There are also some hybrid DVR systems that are compatible with newer IP cameras that are connected by RJ45 network cables, which means you can create or upgrade a security system using both types of cameras.

Typical DVR. You can easily identify it by the bnc inputs at the back.

What’s the main difference between NVR and DVR?

With different ways to process the videos, the NVR and DVR have to use different type of cameras, which shows their biggest difference: A DVR uses analog CCTV cameras that are connected via a coax cable, while an NVR uses IP cameras (standalone network devices) that transmit information via a network cable.

In a nutshell, a NVR recorder is a network video recorder for IP cameras, which helps to expand storage and manipulate multiple cameras. By contrast, the DVR is not only a storage media for analog CCTV cameras but also a video processor that analog cameras must live with.

NVR Security Systems Pros:

1.  Flexible camera/recorder placement. As mentioned before, the NVR inputs videos from the network. That’s to say, you can place the NVR virtually anywhere as long as it is on the same LAN network as the IP cameras. Even the IP cameras placement is easier, since all you have to do is to have the camera on the same network (LAN).

2. Minimal wiring required. The NVR security system makes the cable work easier. The Wi-Fi NVR visits cameras through the network wirelessly, and the PoE NVR connects with all cameras with one single cable via a PoE switch. Both are impossible for DVRs which will need exactly point-to-point connection

3. Works with cameras that produce greater resolutions and other smart features. Because of the nature of the NVR, you can enjoy higher quality images with 4MP, 5MP, 4K (8MP) or 12M IP cameras, which is out of the question for analog cameras in a DVR security system. At the same time the IP cameras offer a variety of smart features such as: heat map, people counting, face detection, intrusion, trip wire etc.

4. Processing video from analog to digital occurs in the camera. Basically the feed that the NVR receives is already processed. This allows the system to be more efficient and will utilizes its resources better.

5. The data of an NVR system can be encrypted for better protection.

NVR Security Systems Cons:

1. Is dependent on network stability. If the network goes down or is affected by other devices, physical obstructions, or weather, it can experience interference or fail to record. However, there are many ways you can try to minimize the influence. Such as putting the cameras and the NVR on separate network, or getting a dual band Wifi NVR system (if using a wireless surveillance system).

2. Potential compatibility issues. Not all IP cameras will work with a certain type of NVR. Generally speaking, is better to get a NVR security system from the same manufacturer/seller.

3. Bandwidth consumption. Due to the nature of IP network cameras, NVR systems do consumes more bandwidth than the DVR kit. However this issue can be manged if the system is set up properly. There’s no such issue on the NVRs with built-in PoE switch.

4. Typically more expensive than DVR systems. Especially if you go for a high-end system.

DVR Security Systems Pros:

1. DVR security systems can be used to upgrade existing CCTV systems to digital using pre-existing wiring. This is their biggest advantage. If you have an an old analog system, you can upgrade to HD-CVI/HD-TVI/HD-AHD with 2MP, 4MP or even 4K HD cameras by keeping the same coaxial wiring.

2. Not network dependent. Since DVR systems are hard-wired, they are not network dependent, therefore they won’t fail due to network outages. Each camera goes straight to the recorder.

3. Money-saving. Price is always an important factor, especially on camera systems. Generally, the DVR security systems are priced less than the NVR ones since the analog cameras are much easier to manufacture with less functions and therefore cheaper than the IP cameras.

DVR Security Systems Cons:

1. Lots of cabling work needed. Each camera will have a separate cable to deal with (this might be a thick Siamese cable). And to run back all the wires from different positions, you will very likely run into some embarrassing situations like drilling holes in the wall or the monitoring places are just out of the cable reach of your cameras.

2. Lower quality videos. Even though the emerging technology has greatly improved the recording quality of analog cameras (such as 2MP, 4MP, or 4K), they still can not catch up with the IP cameras clarity and performance.

3. Higher maintenance cost. As mentioned, the DVR system transmits signal via coax cable, which is much more vulnerable to the adverse environments like the rain or strong wind. If they are exposed outside, you’ll much likely to pay an extra bill in fixing the cable issues.

4. Lots of potential issues to deal with. The DVR system, not to say it is outdated but it is definitely not something futuristic, gains decreasing market share every year.

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