DVR Calculator


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Online DVR Calculator
Use with Security Labs SLD274, SLD275, SLD276, & SLD281 digital video recorders.

Determine the hard drive (HDD) size required to record for a specific duration based on: 1) Quality setting (amount of compression), 2) Resolution (image size), 3) Record speed (frame rate), 4) Record time

Determine record duration available based on: 1) Quality setting , 2) Resolution , 3) Record speed, 4) HDD size

SECURITY LABS DVR MODEL: 4CH (SLD274) 8CH (SLD275, SLD281) 16CH (SLD276)
Recording capacity Recording time
Video system	Select NTSC in North America
Quality
Resolution
Record speed
Record duration
HDD size	160GB or 250GB HDD is factory installed
(C) SLI, 2007


Solving for RECORDING TIME example:

An SLD275 8 channel DVR is used. The record duration (amount of time that can be recorded before the hard drive is full) needs to be determined for the following settings:
QUALITY: HIGH
RESOLUTION: 720x240 (full screen picture)
RECORD SPEED: 1/10*
HDD SIZE: 160GB (factory installed drive)

The calculator determined that the DVR record time for the above settings is 194.18 hours.

* The record speed setting is a portion of the maximum system or global record speed. Setting this to "1/1" means use the maximum record speed. The maximum speed is shown when resolution is selected and is denoted as IPS (images per second).

In the above example, 1/10 of the maximum system IPS:
120ips x 1/10 = 12. To determine how often each camera will record a picture, divide 12 by the number of cameras being recorded with the DVR. If 10 cameras are recorded, each camera will record 1.2 images per second. Observe that if the record speed is changed to "1/1", the cameras will now be recorded at 12 images per second (10 times as fast) and the record time of the DVR (until the hard drive is full) is now smaller, only 19.41 hours.

Each setting can be adjusted until the desired outcome is achieved.