Security cameras or video surveillance have different technologies to record everything that happens in front of the lens, beyond qualities as image quality such as megapixels, optical sensors, and processors, we will find something essential that is to identify if you need to use the technology DVR or NVR. But what is the real difference between a DVR and an NVR?.
The DVR by its acronym Digital Video Recorder is a video recorder in digital format, this means that it records the video signal on a digital medium which can be manipulated by software later. The most common is to find that a DVR requires one or more hard drives such as a USB memory or micro SD memory to store the information. Here the important point is that a DVR is still ” analog ” since although it records the video digitally, it is transmitted to the device through a coaxial cable where we have a bandwidth limitation, for example, to pass a video from 2 megapixels 30 frames and a 4-megapixel video will go at a maximum of 15 frames per second.
An NVR is the evolution of the DVR, NVR means Network Video Recorder and the network section is due to the fact that unlike the DVR in the case of the NVR the recording will come through the network and many things can be done through the network where Unlike the DVR that we use coaxial cable in the NVR, ethernet cable is used to connect the camera to the video recorder device or, failing that, directly to the network and from the network to the video recorder device.
Advantages of a DVR
The main advantage of acquiring a DVR system is the cost of both the device and its components. Nowadays, recognized brands such as Dahua or Hikvision can offer you DVR solutions for really cheap costs, apart from the fact that they are plug and play since, as I mentioned, a coaxial type cable is used for its connection, which is already built. In the market you can find DVR Kits with costs from 150 USD (3 thousand Mexican pesos) to which you only have to add a hard drive and that’s it, you can install it yourself in your home or office and connect it to the internet and be able to see the internet cameras is not so much a problem because you will find the manual and the connection tutorial easily.
Another advantage of buying a DVR is that it can be easily modified to your liking in terms of expanding the cameras you need later, for example, you buy an 8-channel DVR with 4 cameras, so there are 4 free channels left and later you just have to buy the cable and the necessary camera (compatible with that model) and connect.
Advantages of an NVR
The NVR is a more complex system than the DVR although in principle they fulfill the same function, the NVR is a microcomputer with a decent processor since it will be in charge of encoding and processing the image received through the network. The main difference between DVR and nvr is that in the nvr the cameras are connected by means of a network cable, you will not be able to use a coaxial cable for its connection, in the same network cable you can send the energy ( POE protocol ) and the signal of video, this is how this camera is assigned as an IP address within the network since I remind you «it is NETWORK«. The main advantage of an NVR is that you can place cameras at longer distances without the need to connect directly to the device because the only requirement is that they are connected to the same network and how they will act as if it were a computer on the data network will be by the same network that the information packets will be sent to be encrypted and recorded in the NVR.
Another advantage of an NVR is that you depend more on the processing capacity than on the port capacity, for example, you can buy an nvr that only has 4 ports (for 4 cameras directly connected) but has enough processor to record another 8 cameras that it can detect through the network. This is unlike the DVR where you necessarily need one port per camera on the computer.
Perhaps the most impressive advantage of an NVR over a DVR is the fact that it can use cameras with many megapixels, since you can use cameras, for example, 12 megapixels at 30 frames per second, which will give you image quality and detail with the that is only dreamed of in science fiction movies but that does exist.
Disadvantages of using an NVR and DVR
- NVR and IP cameras are considerably more expensive than DVR components.
- The hard drive to store information in an NVR has to be an HDD designed for network video surveillance since using an unsuitable one will end up failing after a year or less. And as you can imagine, it is also more expensive.
- A marked disadvantage of installing a DVR for surveillance is that it will not always offer you 30 FPS ( IPs ) since it depends on the brand and quality. For example, Hikvision and Dahua offer up to 2 megapixels (1080P quality) and a speed of 30 frames per second, while fewer commercial brands such as Steren, Costco, Sams, Office Depot, etc. only support 15 frames at FUll HD quality, which it makes you have a robotic image.
- The configuration of an NVR can be complicated, there are brands like ACTI that are so jealous that they issue a license per camera and you have to buy licenses for each channel apart from being limited in the recording settings. If we add that from the NVR you have to go to a switch and from the switch to another and from that other to the router and the cameras are connected in the 3 named levels, it can drive you crazy to locate the IPs if it does not detect them automatically.
- In a DVR, connecting 8 or more coaxial cables + the power cable will result in a branch with a giant diameter, difficult to hide, and more difficult to manipulate.
And those are some of the most marked differences between NVR and DVR. Most of the companies that are dedicated to creating video surveillance systems have released hybrid products also called hybrid DVRs or depending on the number of technologies they can support they can be Trihybrid or Pentahybrid, example in Dahua are Dahua HCVR vs XVR models where The main quality of these devices is that they support connections by the traditional analog cable from the factory, but additionally they can detect cameras in other technologies such as IP .that are in the same work network so that you can access them to start recording, then a DVR does the function of an NVR with the difference that it usually cannot add as many IP cameras as analog cameras, that is, if it is of 8 analog channels will support at most another 8 over IP.
The advantage of a Hybrid DVR is that it brings you the best of both worlds and at a more affordable price than an NVR with a limited number of channels and a limited amount of storage since a high-capacity NVR can support multiple hard drives. to record in all the cameras for long periods of time but a hybrid DVR is usually found in configurations of 2 or 3 hard drives which will not always be enough for 30 days of recording at full quality.
Advantages and Disadvantages of a DVR Vs NVR
Compression H264 vs 264+ vs 265
Finally, let’s talk about the recording codecs, in a DVR we will normally find that they only record in h264, this is a compression rate that was ideal a few years ago before the output of 2K or 4K resolutions with which they had to leave the H264+ and H265 codecs that compress the video even more to occupy the same space but recording at the higher video quality.
Comparison table of how many days a DVR can record with a 1TB hard drive storage in H.264 H264+ and H265 formats.
In the example, in the table, I used 4 cameras recording at 30 frames per second in FULL HD 1080P quality with the 3 different current codecs and as you can see the difference is more than drastic. That is why if you are going to acquire a surveillance system, this point to review is important that it has H264+ compression or preferably H265, with which in less space you will store a greater amount of time.