Why do video surveillance hard disk recorders use special hard disks for video storage?

There is always a perception in industry that HDD DVRs need dedicated HDDs for monitoring! ! ! Why is this? Next, let's talk about difference between hard drive for monitoring and hard drive of a regular PC

1. Hard Drive Life

Regular computer hard drives start up at full speed when turned on, and instantaneous current can reach 2A or even more. (Therefore, some customers cannot read data from hard disk when turning on normal computer hard disk, and it will be normal after switching to a high A-number power adapter. Customers can refer to this solution in actual use) < /p>

When monitored hard drive is turned on, it will slowly accelerate and inrush current will be less than 2 amps.

Because monitoring system usually installs multiple hard drives, a large inrush current will be generated at time of startup. If it is a normal computer hard drive, power supply will be unbearable or even burned out. In addition, monitoring system usually does not have high requirements for transfer speed of hard disk, but often reads and writes small amounts of data. Therefore, it is necessary to optimize design of read-write mechanism of magnetic head according to read-write characteristics of monitoring system in order to extend service life of magnetic head.

The theoretical mean uptime of monitoring hard disk is much longer than that of a normal computer hard disk, and stability and reliability are higher.

2. Permanent difference in working hours

The design of conventional computer hard drives is based on 8x5 format. 8×5 refers to a normal computer hard disk running 8 hours a day, 5 days a week (Hard disk operation means that hard disk is in a read and write state. Pay special attention to fact that there are two states after power on hard drive: working state and standby Working state - hard disk reads and writes, and standby state - hard disk does not read or write, but is in standby mode.)

The monitoring hard disk is designed and engineered to meet requirements of a 24/7 enterprise-grade environment. 24×7 means work 24 hours a day, 7 days a week (i.e. work continuously).

Therefore, regular computer hard drives are not suitable for long continuous reading and writing. If ordinary computer hard disks need to be continuously read and written for a long time, it will severely damage hard disk, causing abnormal sounds, read and write errors, suspension and other problems on hard disk, which lead to permanent damage to hard disk.

The hard disk recorder works continuously all year round, so hard disk is required to be able to work continuously for a long time. A monitoring hard drive can meet this requirement.

3. Launch difference

All 3.5" hard drives contain a drive system thattherefore, when hard drive is turned on, situation is similar to situation when engine is turned on: that is, at initial moment of time, a large starting current appears. power on to complete hard disk boot. If external hard drive power system cannot guarantee sufficient current when hard drive is turned on, hard drive will not start, making it unusable. And if this happens many times, it is easy to damage hard drive. Because hard drive motor is powered by 12 VDC from an external power system, 12 VDC is used as a reference when estimating hard drive's starting current.

The starting current of conventional computer hard disks is typically 2.8 to 3.2 A. The starting current of a monitoring hard disk is up to 2.0 A. Hard disk DVRs often use multiple hard disks for data storage. As an example Take installation of 8 hard drives: starting current of ordinary computer hard drives is 2.8 × 8 = 22.4A, and lowest power consumption is 22.4A × 12V = 268.8W. The starting current of special hard disk DVR is 2.0A×8=16A, and maximum power consumption is 16A×12V=192W.

It can be seen that with same number of hard disks, monitoring hard disk has less external power system requirements (when supporting an external power supply with same output power, number of dedicated DVR hard disks that can be installed will be larger).

Explanation: In case of above example, if external power system can only guarantee 250W, when using ordinary PC hard drives, some hard drives can be recognized, some hard drives are not recognized, and there is no pattern. .

4. Differences in power consumption and heat dissipation

Operating power here refers to power consumption of hard drive in its normal read/write state. The working power consumption of PC hard disk is usually about 14.5W, and working power consumption of monitoring hard disk is usually about 8W.

You can see that power consumption of monitor's hard drive is only 55% of that of a typical computer hard drive. Low power consumption is not only important for power supply system, but also important for heat dissipation of a hard disk DVR system (approximately 75% of operating power is converted into heat). In hard disk DVR, if 8 hard disks are installed, total power consumption of ordinary PC hard disk is 14.5W × 8 = 116W, and total power consumption of DVR's dedicated hard disk is 8W × 8 = 64W. . If conventional PC hard drives are used, it can be imagined that in such a small space as a digital video recorderbackground with a hard disk, there is such a strong heat source that it requires a high heat dissipation from system. has a reasonable ambient temperature (0 ~ 60 ℃), hard disk system should dissipate effectively. And use of a dedicated DVR hard disk greatly improves heating situation --- reduces heat dissipation requirements of system, and makes system more adaptable to environment.

5. Transmission difference

In addition to transfer mode of traditional computer hard disk, monitoring hard disk also introduces a new transfer mode, continuous transfer mode at up to 65MB/s.

With continuous transmission mode, HDD supports streaming media more reliably and fully guarantees smooth and stable playback of HDD DVR during recording. This is a feature that other hard drives do not have.

6. Price difference

Compared to ordinary computer hard drives, surveillance hard drives are almost same price, but differ in special technical support, former focuses more on performance, while latter focuses on stable reading and writing. Relatively expensive, only enterprise-grade hard drives, because requirements are more stringent