Dahua nvr4208-8p User Manual

391
8 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
i
q
that is the capacity of each channel
needed for each hour, unit Mbyte.
102436008 
ii
dq
(1)
In the formula:
i
d
means the bit rate, unit Kbit/s
Step 2: After video time requirement is confirmed, according to Formula (2) to calculate the storage
capacity
i
m
, which is storage of each channel needed unit Mbyte.
i
m
=
i
q
×
i
h
×
i
D
(2)
In the formula:
i
h
means the recording time for each day (hour)
i
D
means number of days for which the video shall be kept
Step 3: According to Formula (3) to calculate total capacity (accumulation)
T
q
that is needed for all
channels in the device during scheduled video recording.



c
i
iT
mq
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)
T
q
that is needed for all
channels in device during alarm video recording (including motion detection).



c
i
iT
mq
1
×a% (4)
In the formula：a% means alarm occurrence rate

Dahua nvr4208-8p Specifications

General

Operating System	Embedded LINUX
IP Camera Input	8 channel
Two-way Talk	1 channel Input, 1 channel Output, RCA
Interface	1 HDMI, 1 VGA
OSD	Camera title, Time, Video loss, Camera lock, Motion detection, Recording
Record Interval	1 ~ 120 min (default: 60 min), Pre-record: 1 ~ 30 sec, Post-record: 10 ~ 300 sec
Ethernet	1 RJ-45 Port (10/100/1000Mbps)
Max. User Access	128 users
Smart Phone	iPhone, iPad, Android
HDD Bays	1
Operating Temperature	-10°C ~ +55°C (+14°F ~ +131°F)
Main Processor	Dual-core embedded processor
Multi-screen Display	1/4/9
Video Detection and Alarm	Motion Detection, MD Zones: 396 (22 x 18), Video Loss, Camera Blank
Alarm input	4
Relay Output	2
Compression	H.265, H.264
Recording Resolution	Up to 8MP
Record Mode	Manual, Schedule (Regular, Continuous), MD (Video detection: Motion Detection, Camera Blank, Video Loss)
PoE	8 ports (IEEE802.3af/at)
Protocols	HTTP, TCP/IP, IPv4/IPv6, UPnP, RTSP, UDP, SMTP, NTP, DHCP, DNS, IP Filter, PPPoE, DDNS, FTP, Alarm Server, IP Search (Support Dahua IP camera, DVR, NVS, etc.)
USB Interface	2 USB2.0
Power Supply	AC 100~240V, 50/60 Hz
Power Consumption	NVR: <10W (without HDD), PoE: Max 25.5W for single port, 130W total
Operating Humidity	10%~90% RH