DVR vs NVR: Which CCTV Recorder Do You Need?

Buying Guides

Everybody calls it “the DVR”. The box in the cupboard under the stairs, the one with the hard drive in it. Half the time it’s actually an NVR, and the difference matters the moment you buy a camera for it, because a camera that suits one kind won’t even plug into the other.

What goes in the back

A DVR (digital video recorder) has a row of BNC sockets on the back, one per camera. Analogue HD cameras send their picture down coax, and the DVR turns it into digital video and records it. All the encoding happens in the recorder.

An NVR (network video recorder) has network ports instead. IP cameras encode their own video and send it over the network as a finished stream, and the NVR’s job is mostly to store it and show it. Most NVRs sold for small systems also have PoE ports, which power the cameras down the same cable.

So the cameras decide the recorder. Not the other way round. Coax cameras need a DVR. IP cameras need an NVR. If you haven’t chosen the cameras yet, IP vs analogue HD is the place to start.

Reading the model number

The model number tells you most of what you need, once you know the code.

The trap is the PoE figure. A recorder’s channel count and its PoE port count aren’t always the same number. A 32-channel NVR very often has sixteen PoE ports, and the other sixteen cameras are expected to arrive through a switch. That’s a normal way to build a big system. It’s also an unwelcome discovery when you’ve already got sixteen cameras up on the brackets, the cable cut to length and pushed through the wall, and nowhere obvious to put a switch that needs its own socket.

Hybrid recorders

Most current DVRs aren’t pure DVRs. HiLook’s DVR-208Q-M1(E) takes TVI, AHD, CVI and old CVBS cameras on its eight coax inputs, and its datasheet lists up to twelve IP camera inputs as well. How many of those you get at once depends on how many coax channels you leave switched on. Dahua call theirs XVR and badge it penta-brid, meaning five signal types on one box.

That’s useful in two situations. A site with working coax cameras can add an IP camera with two-way audio at the back door without a second recorder. And an old system can move to IP gradually, a camera at a time, as the coax cameras fail. Read the IP channel figure on the datasheet before you plan round it, and the maximum IP resolution too. These HiLook DVRs top out at 6MP on their IP inputs.

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The figures that matter on a datasheet

Incoming bandwidth (NVRs). This is the total video the recorder can take in. The HiLook eight-channel NVR handles 80 Mbps. Eight 4MP cameras at around 5 Mbps each come to 40 Mbps, which is comfortable. Eight 8MP cameras at 10 Mbps use the whole 80 and leave nothing for the extra a colour camera asks for at night. Our piece on sizing an NVR has the full table.

Decoding capacity. How many cameras it can show on screen at once at full resolution. The same HiLook NVR decodes two 8MP streams at a time. Fine for watching footage back. Less fine if you want sixteen 4K cameras live on a big monitor at the counter, which needs a bigger recorder.

Encoding resolution (DVRs). This is the one that catches people. A DVR does the encoding itself, so it records at its own resolution limit, whatever the camera can manage. Recorders sold as “Lite” record below the full figure to keep the price down. The HiLook DVR-204Q-M1(E) and DVR-208Q-M1(E) list 1080p at 15 frames per second as their encoding limit. That’s plenty for a front door a few metres away. If you want every pixel a 5MP or 8MP coax camera can produce, buy a DVR whose encoding figure matches the camera, such as HiLook’s 8MP DVR-208U-M1.

Drive bays. One bay is normal up to eight channels. Two or more lets you add capacity later instead of swapping the drive, and how much you need is worked out in what size hard drive for CCTV.

PoE on the recorder or on a switch

For up to eight cameras, the recorder’s own PoE ports are the tidiest build. Past that, or where the cameras are spread round a large building, a separate PoE switch near each group of cameras usually works out better, and a dead switch then doesn’t take the recorder down with it. PoE for CCTV explained covers budgets and cable.

Which one to buy

With new cable going in, buy an NVR and IP cameras. With coax already in place, buy a DVR and make it a hybrid, so IP cameras can join later. That same hybrid covers a mixed site with a few cameras of each kind.

Whichever you choose, buy more channels than you need today. People add cameras. They almost never take them away.

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  NVR recordersFor IP cameras. Four to 128 channels, most of the small ones with PoE built in.
  
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  DVR recordersFor coax cameras. Hybrid 5-in-1 models take IP cameras as well.
  
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  OEM Hikvision 8CH PoE NVREight PoE ports, 80 Mbps incoming and AcuSense detection.
  
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  HiLook 4CH 5-in-1 DVRFour coax inputs plus IP channels, with audio over coax.
  

If you want a second opinion on a recorder before you order, send the camera list through our contact form. And if you’re starting from nothing, the CCTV kit buying guide puts the recorder in context with everything else.

Frequently asked questions

What is the difference between a DVR and an NVR?

A DVR records analogue HD cameras that connect by coax and does the video encoding itself. An NVR records IP cameras that connect by network cable and send already-encoded video.

Can I use IP cameras with a DVR?

With a hybrid DVR, yes. Most current DVRs, HiLook’s included, accept a number of IP cameras over the network as well as coax cameras. The count and the maximum resolution vary by model.

Can I use analogue cameras with an NVR?

Not directly. An NVR only takes network cameras. You would need an encoder to convert each analogue feed, which rarely makes sense when a hybrid DVR does the job.

What does /8P mean on a recorder?

It is the number of built-in PoE ports. An NVR ending /8P can power eight IP cameras directly from the recorder without a separate switch.