The document discusses four main types of computer hard drives: 1) Parallel ATA (PATA) drives were the original type and used parallel signaling. 2) Serial ATA (SATA) drives transfer data faster using serial signaling and have thinner, more flexible cables. 3) Small Computer System Interface (SCSI) drives are faster, more reliable, and better for large data storage and movement. 4) Solid state drives (SSD) have no moving parts, provide faster access, are more durable and shock resistant, and use less power than traditional hard drives.

1. Types of Hard Drive
Dr. Kamal Gulati

2. Four types of Hard Drives
• Parallel Advanced Technology Attachment (PATA)
• Serial ATA (SATA)
• Small Computer System Interface (SCSI)
• Solid State Drives (SSD)

3. 1.) Parallel Advanced Technology Attachment
(PATA)
• These were the first types of hard disk drives and they made use of
the Parallel ATA interface standard to connect to computers.
• These types of drives are the ones we refer to as
• Integrated Drive Electronics (IDE) and
• Enhanced Integrated Drive Electronics (EIDE) drives.

4. A hard disk drive (PATA type)

5. 2.) Serial ATA - SATA
• SATA drives can transfer data faster than PATA types by using serial
signalling technology.
• SATA cables are thinner and more flexible than PATA cables.
• They have a 7-pin data connection, with cable limit of 1 meter.
• Disks do not share bandwidth because there is only one disk drive
allowed per SATA controller chip on the computer motherboard.
• They consume less power. They only require 250 mV as opposed to
5V for PATA.

6. A SATA Hard Disk Drive Pin Out

7. 3.) Small Computer System Interface
SCSI
• Devices that are connected in a SCSI have to be terminated at the
end. Here are some of their advantages.
• They are faster.
• They are very reliable.
• Good for 24/7 operations.
• Have a better scalability and flexibility in arrays.
• Well-adapted for storing and moving large amounts of data.

8. Small Computer System Interface

9. 4.) Solid State Drives
• They are latest in drive technology that we have in the computer
industry.
• Here are some of their advantages.
• Faster data access.
• Less susceptible to shock.
• Lower access times and latency.
• Durability.
• Less power usage.

10. A Solid State Drive (SSD)