Number of cameras:
Be sure to purchase a DVR that supports the number of cameras that you need now as well as what you may need in the future.

Frames Per Second (fps):
Calculate your fps per camera by taking the total fps of the system and dividing it by the number of cameras that you have. For example, a 4 camera system with 30 fps would give you about 7 fps per camera. A low fps per camera (3 fps per camera) is adequate for most security needs. If your application involves money counting, as in casinos or bank telling, then you will want to purchase the highest fps available.

Card, Stand-alone or Embedded:
Card systems are good if you have a spare computer with the compatible parts and operating system and the expertise and time to build it, you can save yourself some money using this do-it-yourself approach. Pre-built PC-based (standalone) systems allow the convenience of just plugging in the cameras and knowing that all of the hardware and software is compatible and pre-tested. Embedded systems are convenient like the PC-based systems. They are designed specifically for the DVR and so remove the risk of operating system errors and lockups. However, the embedded systems do not allow remote viewing and they are only currently available in 30 fps.

Remote viewing:
You can view your cameras remotely either by connecting directly to the system using a modem, or through the internet, or through your company’s network. The remote viewing feature is not available in the embedded systems.