Bandwidth
The maximum data stream in Mbit/s that the NVR is capable of processing when recording and displaying. The throughput parameter is specified as the maximum incoming/outgoing speed, or as the sum of incoming and outgoing streams (total throughput). It is calculated in such a way that the throughput exceeds the total flow of all IP cameras connected to the DVR, and another 25–30% is put in reserve for playing video or viewing it via network access.
Max. total capacity
The largest total storage capacity with which the recorder is able to work correctly. By default, it is indicated only for internal media with a SATA interface (see above), however, in some models, data is also provided separately for external devices connected via eSATA.
Note that the limit on the total capacity follows from the fact that each individual port has its own limit on the capacity of the drive. In this case, the maximum capacity is distributed equally between the ports. This should be taken into account when choosing drives for the registrar: for example, in a 32 TB model with 8 SATA connectors, the limit for each connector will be 32/8 = 4 TB. This means that installing two internal 8 TB disks in such a registrar will not work, although their total capacity will be less than the maximum.
Total PoE power
The total power that the NVR is capable of delivering to all PoE outputs.
See above for details on such exits; here we only recall that the general idea of PoE is to supply power over the same Ethernet cable that transmits data. The total power is given for models in which there are more than one such connectors; it allows you to estimate the total power consumption of all PoE devices that can be connected to the NVR at the same time.
There are two important things to keep in mind when choosing a specific value. First, when multiple ports operate, the energy is usually shared equally among them; at the same time, the total power of the registrar does not always correspond to the sum of the maximum powers of all PoE outputs. For example, a model with 8 ports of 30 W each may have a total figure of not 240 W (8 * 30 W), but only 100 W. In fact, this discrepancy means that with the simultaneous use of all connectors, each of them will be able to deliver not 30 W, but a maximum of 100/8 = 12.5 W. The second point is that the total power consumption of the load should ideally be no higher than 75% of the claimed total PoE power — this provides an additional guarantee in case of malfunctions.
Power supply
The standard supply voltage of the recorder.
It is worth considering that almost all modern recorders are designed for direct connection to an outlet (110 - 240 V). This paragraph also indicates the voltage at the input of the device itself. That is, if the specifications indicate a value less - for example, 12 V or 24 V - this means that the recorder uses an external power supply (which is usually included in the kit). But models for 100 - 240 V use a built-in power supply.
Operating temperature
The range of ambient air temperatures at which the recorder is guaranteed to remain fully operational, and the likelihood of interference and failures is minimal. In most cases, recorders are installed indoors with a quite favorable microclimate, while the operating temperature range is quite extensive — for example, a value of -10 ... +55 °C is not unusual. Therefore, you should pay attention to this indicator only when installing in difficult conditions — for example, in an unheated warehouse or in a production room with elevated temperatures.
