QSD42908C8 User’s Manual
Appendix B: HDD Capacity Calculation
To calculate total capacity needed by each DVR according to video recording (video recording type and video file storage time).
Step 1: Use Formula (1) to calculate storage capacity qi that is the capacity of each channel
needed for every hour: unit Mbyte.
.
qi = di ⎟ 8⋅ 3600 ⎟1024 | (1) |
In the formula: di means the bit rate, unit Kbit/s
Step 2: After video time requirement is confirmed, according to Formula (2) to calculate the storage capacity mi , which is storage of each channel needed unit Mbyte.
| mi = qi × hi × Di | (2) |
| In the formula: |
|
hi | Represents the recording time for each day (hour) |
|
Di | Represents number of days for which the video shall be kept |
|
Step 3: Use Formula (3) to calculate total capacity (accumulation) qT | that is needed for all | |
channels in the DVR during scheduled video recording. |
| |
c
qT = ∑ mi
i=1
In the formula: c represents total number of channels in one DVR
Step 4: Use Formula (4) to calculate total capacity (accumulation) qT that is needed for channels in DVR during alarm video recording (including motion detection).
c
qT = ∑ mi ×a%
i=1
In the formula：a% means alarm occurrence rate
(3)
all
(4)
92
