NVR vs DVR: the difference, and which one to choose
The recorder follows the cameras. A DVR records analog and HD-over-coax cameras on coax cable; an NVR records IP cameras over the network. Everything else, from cabling to resolution, follows from that one choice.
NVR and DVR side by side
| Aspect | DVR | NVR |
|---|---|---|
| Cameras | Analog and HD-over-coax: AHD, HD-TVI, HD-CVI | IP cameras |
| Cable to each camera | Coax for video plus a power pair, or power over coax | One Ethernet cable for video, power (PoE) and control |
| Where the video is encoded | In the recorder | In each camera |
| Resolution | Up to 8 MP (4K) | 8 MP is common; 12 MP and multi-sensor cameras exist |
| Cable run | Often 300 to 500 m on RG59 for HD formats, depending on format and resolution | 100 m per Ethernet run; longer through switches or extenders |
| Where cameras connect | Directly to the recorder, point to point | Anywhere on the network: recorder PoE ports, switches, other buildings |
| Analytics | Mostly in the recorder | In the camera, the recorder, or both |
| Best for | A site that already has coax | New installations |
Choose an NVR when
The site is new or being recabled, you want resolution above 8 MP, analytics in the cameras, or cameras spread across buildings and networks.
Choose a DVR when
Sound coax already runs to every camera position and replacing it would cost more than the gain in picture quality.
Choose a hybrid when
You keep the coax cameras for now and add IP cameras where new cable goes in. Hybrid recorders, sold as XVR or HVR, record both.
Sizing an NVR
- Channels. One per camera, plus room for the cameras the client will add.
- Incoming bandwidth. The sum of every recorded stream must fit the recorder's input limit, not just its channel count.
- Storage. Bitrate times retention decides the drives; check the bays and the largest drive each bay takes.
- PoE. Built-in PoE ports have a total power budget. Cameras with IR, heaters or PTZ can exceed it before the ports run out.
Work it out with the storage calculator, the bandwidth calculator and the PoE budget calculator.
Recorders in CCTVplanner
- The NVR catalog has a page for each recorder with channels, incoming bandwidth, maximum resolution, drive bays, built-in PoE ports and budget, codecs, RAID and ONVIF, taken from the datasheet.
- In a design, the planner totals the cameras' bandwidth, storage and PoE draw and checks them against the recorders and PoE switches you place.
- The recorder, drives and switches land in the bill of materials and the quote with the cameras.
NVR and DVR questions
What is the difference between an NVR and a DVR?
A DVR records analog and HD-over-coax cameras and encodes their video itself. An NVR records IP cameras, which encode their own video and send it over the network, usually powered by PoE through the same cable.
Which is better, NVR or DVR?
For a new installation, an NVR with IP cameras: higher resolution, one cable per camera with PoE, analytics in the camera and cameras anywhere on the network. A DVR makes sense when good coax is already in the walls.
Can I connect IP cameras to a DVR?
Not to a pure DVR. Hybrid recorders, sold as XVR or HVR, take both coax cameras and a number of IP channels.
Can I use analog cameras with an NVR?
Only through an encoder that turns each analog camera into an IP stream, which usually costs more than moving to a hybrid recorder.
Does an NVR need the internet?
No. It records on the local network. The internet is only needed to view the cameras from outside the site.