User`s manual

274
7 Appendix A HDD Capacity Calculation
Calculate total capacity needed by each device according to video recording (video recording type and
video file storage time).
Step 1: According to Formula (1) to calculate storage capacity q
i
that is the capacity of each channel
needed for each hour, unit Mbyte.
q
i
 d
i
 8  3600  1024
(1)
In the formula: d
i
means the bit rate, unit Kbit/s
Step 2: After video time requirement is confirmed, according to Formula (2) to calculate the storage
capacity m
i
, which is storage of each channel needed unit Mbyte.
m
i
= q
i
× h
i
× D
i
(2)
In the formula:
h
i
means the recording time for each day (hour)
D
i
means number of days for which the video shall be kept
Step 3: According to Formula (3) to calculate total capacity (accumulation) q
T
channels in the device during scheduled video recording.
that is needed for all
c
q
T


m
i
i1
(3)
In the formula: c means total number of channels in one device
Step 4: According to Formula (4) to calculate total capacity (accumulation)
q
T
that is needed for all
channels in device during alarm video recording (including motion detection).
c
q
T


m
i
×a% (4)
i1
In the formula a% means alarm occurrence rate