What is Hard Disk Drive (HDD)?

Last Updated: 2021-09-17

概要: A hard disk drive (HDD), a non-volatile data storage device, uses magnetic storage to store and restore digital data. HDD is usually the most substantial data storage hardware device installed internally in a computer. It can store an operating system, software, and most other files.

The Capacity of An HDD

In late 2019, the highest-capacity of HDDs was 16 TB.

As reported by an operating system, the capacity of an HDD is smaller than that stated by the manufacturer because space should be left for the operating system, data redundancy, and file system structures.

Data Transfer Rate of HDD

Data transfer rate can be measured by using special file generator tools to write a large file to disk and then reading back the file. File system fragmentation and layout of the data are the key factors that influence the transfer rate.

By 2010, the data transfer rates of a typical 7,200-rpm desktop HDD was up to 1,030 Mbit/s. This rate, which depends on the track location, is higher on the outer tracks and lower on the inner tracks.

HDD data transfer rate depends on the data recording density and the rotational speed of the platters. Advancing density becomes the primary way to increase the transfer rate, as rotational speed is limited by vibration and heat. To achieve higher speeds, a more powerful spindle motor is needed to create more heat.

How Does an HDD Works?

Hard disk drive, unlike volatile storage, retains its data even when powered off. This means that when you restart a computer, your HDD is also powered down, but all the data can be accessed when it’s back on.

How Does Hard Drive Works?

  • The hard drive contains a rotating platter with a thin magnetic head. Moving with an actuator arm, the heads can read and write data to the disk.
  • A modern HDD can save over a trillion 0/1 bits per platter, so some of the North and South spots are very small.
  • The Flash storage is made of chips and is gradually replacing such kind of rotating hard drives. Flash chips are something inside USB storage keys and camera SDHC memory cards.

Data Recovery of An HDD

Hard drive disk is a vital medium to store data, but sometimes it will face unforeseen problems, which may cause data loss. Therefore, HDD data recovery is an inevitable issue.

  • Make a backup regularly: It’s the simplest way to avoid data loss.
  • Turning to the HDD recovery company: Most companies attach great importance to after-sale services, so you can ask the company for help once data loss occurs.
  • Move platters and heads to a new drive: If the spindle motor is corrupted, you can move the platters and heads to a new disk.
  • Use a data recovery app: If the above methods fail, using a 數據恢復軟件 is the most effective way.

Let take Bitwar 檔案救援 software as an example:

Steps to Recover Lost Data from HDD with Bitwar Data Recovery

Step 1: Download and install the Bitwar 檔案救援 software.

Step 2: Choose the HDD where you lost data.

Step 3: Select Quick Scan mode at first (if Quick Scan fails, try Deep Scan again).

Step 4: Choose the file types you need.

Step 5: Preview and recover files.

To Conclude

Hard drive disk (HDD) is inseparable in daily life, and there are many brands of HDD to choose from.

I hope this article gave you a complete impression of hard drives.



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