Digital
Video
Recorder
User
Manual
Appendix A HDD Capacity Calculation
Please use the below formula to calculate total HDD capacity needed for the DVR
according to video recording requirement (Recording resolution and Time period).
Step 1: Use the Formula (1) to calculate storage capacity
that is the capacity for one
camera/hour, in unit Mbyte.
i
q
1024
3600
8
÷
×
÷
=
i
i
d
q
(1)
In the formula:
= Bit rate, unit Kbit/s
i
d
Step 2: Based on the requirement on “Recording Time”, use the Formula (2) to calculate
the storage capacity
, in unit Mbyte.
i
m
i
m
=
×
×
(2)
i
q
i
h
i
D
In the formula:
i
h
= Recording time for each day (hour)
i
D
= Number of days for which the video shall be kept
Step 3: Use the Formula (3) to calculate total capacity (accumulation)
that is needed
for all channels in the DVR during
scheduled video recording
.
T
q
∑
=
=
c
i
i
T
m
q
1
(3)
In the formula:
c
= Total number of cameras in one DVR
Step 4: Use the Formula (4) to calculate total capacity (accumulation)
that is needed
for all channels in DVR during
alarm video recording (including motion detection)
.
T
q
∑
=
=
c
i
i
T
m
q
1
×
a%
(4)
In the formula:
a%
= alarm occurrence rate
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