Dahua NVS1604HF-A, User Manual

Page: 144 / 158

144
Appendix A HDD Capacity Calculation
Calculate total capacity needed by each NVS according to video recording (video recording type
and video file storage time).
Step 1: According to Formula (1) to calculate storage capacity that is the capacity of each
channel needed for each hour, unit Mbyte.
(1)
In the formula: means the bit rate, unit Kbit/s
Step 2: After video time requirement is confirmed, according to Formula (2) to calculate the
storage capacity , which is storage of each channel needed unit Mbyte.
= × × (2)
In the formula:
means the recording time for each day (hour)
means number of days for which the video shall be kept
Step 3: According to Formula (3) to calculate total capacity (accumulation) that is needed for
all channels in the NVS during scheduled video recording .
(3)
In the formula: means total number of channels in one NVS
Step 4: According to Formula (4) to calculate total capacity (accumulation) that is needed for
all channels in NVS during alarm video recording (including motion detection) .
× a% (4)
In the formula
：
a% means alarm occurrence rate
i
q
1024 3600 8
   
i i
d q
i
d
i
m
i
m
i
q
i
h
i
D
i
h
i
D
T
q



c
i
i T
m q
1
c
T
q



c
i
i T
m q
1