The difference between ordinary hard drives and surveillance-specific hard drives
Although the appearance of DVR special hard drive is no different from that of ordinary PC hard drive, in terms of functions and parameters, DVR special hard drive is more suitable for professional use. Their differences are as follows:
1. Applicable environment
Ordinary PC hard drive
Ordinary PC hard drives are designed to meet the continuous development trend of PC applications - more reliable system data storage, diverse application support and faster storage response time.
Relatively reliable system data storage means that under a hard disk (including array) system, the hard disk system can ensure reliable and safe storage of multiple system data. Diversified application support means that the hard disk can support a variety of application environments: PC desktop applications, multimedia applications, games, etc.
DVR dedicated hard drive
The DVR special hard drive is designed to meet the storage requirements of digital hard disk recorders for system data and digital image information.
The DVR dedicated hard drive’s reliable support for system data is extremely stable. This is related to the system characteristics of digital hard disk video recorders. The system of PC-type digital hard disk video recorders is quite single (it is impossible for multiple systems to coexist), and the applications supported in the system are specially customized for digital hard disk video recorders (there are no coexistence of multiple applications); while embedded digital hard disk video recorders generally do not have the concept of a system, and their systems are all built-in and have nothing to do with the hard disk.
Special hard drive for DVR perfectly meets the requirements of digital hard disk recorders for storing and playing back digital images in the form of files, and the hard drive is optimized for the recording and playback characteristics of digital hard disk recorders to fully ensure support for streaming media.
2. Specific differences
An ordinary hard drive will start at full speed when powered on, and the instantaneous current may reach 2 amps or even higher. The monitoring hard disk will accelerate slowly when starting up, and the starting current will be controlled below 2 amps. Because multiple hard disks are usually installed in the monitoring system, a large starting current will be generated at the moment of startup. If it is an ordinary hard disk, the power supply will be unbearable and may even burn out.
In addition, the monitoring system generally does not have high requirements for the transmission speed of the hard disk, but it will frequently read and write small amounts of data. Therefore, it is necessary to optimize the structure of the magnetic head reading and writing mechanism according to the reading and writing characteristics of the monitoring system to extend the life of the magnetic head. The theoretical average trouble-free running time of monitoring hard drives is much longer than that of ordinary hard drives, and the stability and reliability are higher.
Difference in continuous working hours
The design of ordinary PC hard drives is based on 8×5. 8×5 refers to the fact that an ordinary PC hard disk works 8 hours a day and 5 days a week (hard disk working means that the hard disk is in a reading and writing state. Special attention should be paid to the fact that after the hard disk is powered on, it has two states: working state and waiting state. The working state is that the hard disk is performing reading and writing work, and the waiting state is that the hard disk is not performing reading and writing work but is in a standby state.)
The DVR special hard drive is designed and developed according to the requirements of 24×7 enterprise-level environment. 24×7 means working 24 hours a day, 7 days a week (that is, working continuously). Therefore, ordinary PC hard drives are not suitable for continuous reading and writing for a long time. If an ordinary PC hard drive is required to read and write continuously for a long time, it will greatly damage the hard drive, causing the hard drive to have abnormal sounds, read and write errors, work suspension and other problems, which will eventually cause the hard drive to be damaged.
Digital hard disk video recorders operate continuously all year round, so the hard disk must be able to work continuously for a long time. The one that can meet this requirement is a special hard disk for DVR.
Start the difference
When the hard drive is powered on and started is similar to the situation when the motor is powered on: that is, a larger starting current will appear during the initial power-up time to complete the hard drive startup. If the external power supply system of the hard disk cannot guarantee sufficient current support during power-on and startup, the hard disk will fail to start, rendering the hard disk unusable. And if this happens multiple times, it can easily cause damage to the hard drive.Since the power supply of the hard disk motor is satisfied by the 12V DC from the external power supply system, the 12V DC current is used as the standard when evaluating the starting current of the hard disk. The starting current of an ordinary PC hard disk is generally between 2.8A and 3.2A. The starting current of the DVR dedicated hard disk is up to 2.0A.
Digital hard disk recorders often use multiple hard disks for data storage. Taking the installation of 8 hard disks as an example: the starting current of an ordinary PC hard disk is 2.8×8=22.4A, and the lowest power consumption is 22.4A×12V=268.8W. The startup current of DVR dedicated hard disk is 2.0A×8=16A, and the maximum power consumption is 16A×12V=192W. It can be seen that with the same number of hard drives, DVR-specific hard drives have lower requirements for external power systems (with the support of external power supplies with the same output power, the number of DVR-specific hard drives that can be installed will be more).
Note: In the above example, if the external power supply system can only guarantee 250W, when using ordinary PC hard drives, some hard drives will be recognized and some hard drives will not be recognized, and there will be no regularity.
Differences in operating power consumption and heat dissipation
The operating power consumption here refers to the power consumption of the hard disk when it is in normal reading and writing state. The operating power consumption of an ordinary PC hard disk is generally about 14.5 watts, and the operating power consumption of a DVR dedicated hard disk is generally about 8 watts. It can be seen that the operating power consumption of a DVR dedicated hard disk is only 55% equivalent to the power consumption of an ordinary PC hard disk. Low operating power consumption is not only of great significance to the power supply system, but also to the heat dissipation of the digital hard disk recorder system (Operation
Approximately 75% of the power consumption is converted into heat energy).
In a digital hard disk recorder, if 8 hard disks are installed, the total operating power consumption of ordinary PC hard disks is 14.5W×8=116W, and the total operating power consumption of DVR dedicated hard disks is 8W×8=64W. If you use an ordinary PC hard disk, you can imagine that there is such a high heat source in such a small space as a digital hard disk recorder, and the heat dissipation requirements for the system are very high. In order to ensure that the hard disk has a reasonable ambient temperature (0~60℃), the hard disk system must be effectively cooled. With the DVR dedicated hard drive, the heating situation is much better - reducing the system heat dissipation requirements and making the system more adaptable to the environment.
Transmission difference
In addition to using the transmission mode of traditional PC hard disks, the DVR dedicated hard disk also introduces a newer transmission mode - uninterrupted transmission mode. The maximum transmission mode is 65MB/S. By introducing uninterrupted transmission mode, the hard disk's support for streaming media is made more reliable, fully ensuring the smoothness and stability of the digital hard disk recorder's playback while recording. This is a feature that other hard drives do not have.
3. Comprehensive explanation
In summary, the difference between ordinary PC hard drives and DVR-specific hard drives is that DVR-specific hard drives fully consider the storage system requirements of digital hard disk recorders. Through the analysis of these requirements, the applicability of DVR-specific hard drives to digital hard disk recorders is further improved, fundamentally solving the storage problem of digital hard disk recorders, and bringing the reliability and stability of digital hard disk recorders to a new level.
Stability is above all else. DVR dedicated hard drives provide the most stable and secure data storage media, reducing service costs for engineers and reducing the risk of data loss for end users. They are the most loyal partners in the monitoring system industry.