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Hard Drives (HDD)

A hard disk drive (HDD) is a storage device used for storing and retrieving digital information (data) HDD retains their data even when powered off, unlike memory RAMs.

There are three types of hard drives: SATA, SSD, and NVMe.

In 2003, SATA (Serial Advanced Technology Attachment) was introduced as the default interface for most desktop and laptop hard drives and referred to as SATA hard drives, but they are rotary hard drives with spinning platters coated with a magnetic material, with a moving needle that writes data to consecutive sectors on each platter.

Most computer HDDs are fitted into an internal drive bay in the computer and connect to the motherboard using a SATA cable.

HDDs can also be used as external devices these are reasonable as backup drives reducing the risk of data loss if the HDD fails.

The two most common form factors for modern HDDs are 3.5-inch for desktop computers and 2.5-inch for laptops.

A single drive can range from 80 GB to 16 TB and are reliable drives if you need a lot of cheap storage and do not need extremely high reads or writes. Since data is physically written to a disk, deleted, and re-written numerous times, it can become fragmented, meaning that different sectors can be spread across different areas of the disk, thereby slowing down the drive. HDDs also are vulnerable to shock or sudden movement since there are moving parts in each drive, which makes them a poor choice for laptops.



  • Low cost.

  • High disk sizes.


  • Not good for laptops.

  • Requires regular de-fragmentation.


SSD stands for Solid State Drive, SSDs do not have moving parts. Instead, the data is stored on non-volatile flash memory. So, there is no needle that must move to read or write data, and this makes them significantly faster than SATA drives. It is difficult to define exact speeds because it varies by manufacturer and form factor, but the lower-performing drives are comparable to SATA drives.

The disadvantage is that they are significantly more expensive and do not come in as many sizes. SSD drives generally range from about 80GB to 2 TB. Since there are no moving parts, these drives are also more durable, and there are form factors built specifically for laptops, making them ideal for storage on the go. But they are still prone to failure.



  • Fast

  • More durable, especially for laptops


  • More expensive than SATA drives

  • Lower disk sizes


Non-Volatile Memory Express, or NVMe Released in 2013, is a type of SSD that is attached to a motherboard fitted with a PCI Express (PCIe) slot. Incredibly fast, PCIe slots were originally designed for graphics cards.


Speeds on NVMe drives can reach an interface rate of 32 Gb/s with a throughput of 3.9 GB/s, useful if gaming or high-resolution video editing.

Most older BIOS do not support booting from NVMe, so installing an Operating System on an NVMe, a motherboard upgrade may be required.

Having worked for a major IT company and saw the distress on customers' faces when their HDDs failed and they lost their data, I always recommend the Cloud Storage option for important data or photographs. Data recovery on failed drives is awfully expensive and not guaranteed.

Protect your data, if you scrap an old computer DO NOT throw away your HDDs as they can be connected to your new computer using a USB adapter. Also, the important data stored on them can be retrieved by a second or third party, meaning they could have access to ALL your personal information, including passwords and bank details, so BEWARE!

Dealing with HDD Error messages and issues

Hard Drive Backup
Typical connection of a hard drive using
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