Storage Devices

Question 1

What does volatile memory mean and why does it matter for storage?

Answer 1

Volatile memory loses all data when power is removed — this is why we need separate storage devices like HDDs or SSDs to retain data long-term

Question 2

What are the main types of storage devices covered in CompTIA A+?

Answer 2

Hard drives (HDD), solid-state drives (SSD), flash drives, memory cards and optical drives

Question 3

How does a hard drive store data?

Answer 3

Using rapidly spinning magnetic platters with a read/write head on an actuator arm that reads and writes data to the platters

Question 4

What are the main mechanical components inside a hard drive?

Answer 4

Spinning platters, a spindle, an actuator arm and a read/write head

Question 5

What are the common hard drive RPM speeds?

Answer 5

5400 RPM, 7200 RPM, 10000 RPM and 15000 RPM

Question 6

How does RPM affect hard drive performance?

Answer 6

Higher RPM means the platter spins faster reducing wait time for data to reach the read/write head — lower latency means faster read/write speeds

Question 7

What are the two standard hard drive form factor sizes?

Answer 7

3.5 inch for desktops and 2.5 inch for laptops and mobile devices

Question 8

What width is a typical M.2 SSD?

Answer 8

22 millimeters

Question 9

What does SSD stand for and what makes it different from an HDD?

Answer 9

Solid-State Drive — it has no moving parts and uses non-volatile memory chips making it significantly faster than a traditional hard drive

Question 10

What standard does a traditional SATA connection use to move data?

Answer 10

AHCI — Advanced Host Controller Interface

Question 11

What is the maximum throughput of a SATA revision 3 connection?

Answer 11

6 gigabits per second

Question 12

What does NVMe stand for and why was it created?

Answer 12

Non-Volatile Memory Express — created to reduce latency and increase throughput by connecting SSDs directly to the PCI Express bus

Question 13

What is the theoretical transfer speed of NVMe over an M.2 interface?

Answer 13

Approximately 20 gigabits per second

Question 14

What does SAS stand for and what throughput does it provide?

Answer 14

Serial Attached SCSI — provides speeds of approximately 22.5 gigabits per second

Question 15

How does SAS compare to SATA in terms of throughput?

Answer 15

SAS (~22.5 Gb/s) is significantly faster than SATA (~6 Gb/s)

Question 16

Why are SAS and SATA connectors slightly different from each other?

Answer 16

To prevent accidentally plugging a SATA drive into a SAS configuration or vice versa

Question 17

What does M.2 replace and what are its advantages?

Answer 17

It replaced mSATA — M.2 requires no additional cables, connects directly to the system board and supports PCI Express speeds

Question 18

What does mSATA stand for?

Answer 18

Mini SATA — a smaller form factor version of the SATA interface used as a transitional technology before M.2

Question 19

What are the M.2 key types and what do they indicate?

Answer 19

B key, M key or both — they designate the type of connectivity and throughput supported; always check motherboard documentation for compatibility

Question 20

What does EEPROM stand for?

Answer 20

Electrically Erasable Programmable Read-Only Memory

Question 21

What is a key limitation of EEPROM-based flash storage?

Answer 21

It only supports a limited number of write cycles — after that threshold the drive can no longer accept new writes though data may still be readable

Question 22

Why are flash drives not recommended as archival or backup media?

Answer 22

Limited write cycles, small capacity and easy to lose — backups should always be stored in an additional separate location

Question 23

What are the common types of flash storage formats?

Answer 23

USB flash drives, CompactFlash (CF), SD (Secure Digital), Mini SD, Micro SD and xD-Picture cards

Question 24

How do optical drives store data?

Answer 24

A laser beam writes microscopic bumps onto the disc surface; a laser then reads those bumps to retrieve data

Question 25

What are the three common optical drive formats?

Answer 25

CD-ROM, DVD-ROM and Blu-ray

Question 26

Why are optical drives considered slow compared to HDDs and SSDs?

Answer 26

The laser-based read/write mechanism is much slower than the magnetic or electronic methods used by HDDs and SSDs

Question 27

True or False: Hard drives are considered non-volatile storage.

Answer 27

True — hard drives retain data even when powered off unlike RAM

Question 28

True or False: A 15000 RPM hard drive has higher latency than a 5400 RPM drive.

Answer 28

False — a higher RPM drive has lower latency because the platter spins faster

Question 29

True or False: SSDs contain spinning platters just like hard drives.

Answer 29

False — SSDs have no moving parts; they use non-volatile memory chips

Question 30

True or False: SATA revision 3 provides up to 64 gigabits per second throughput.

Answer 30

False — SATA revision 3 provides up to 6 Gb/s; 64 Gb/s per lane is associated with PCI Express

Question 31

True or False: NVMe connects to the PCI Express bus for higher throughput.

Answer 31

True

Question 32

True or False: SAS and SATA connectors are identical and interchangeable.

Answer 32

False — they are slightly different by design to prevent accidental cross-connection

Question 33

True or False: M.2 drives require separate data and power cables.

Answer 33

False — M.2 drives plug directly into the M.2 slot on the system board with no additional cables

Question 34

True or False: mSATA was a permanent long-term replacement for standard SATA.

Answer 34

False — mSATA was a transitional stopgap technology before M.2 became the standard

Question 35

True or False: Flash drives are an excellent choice for long-term data archiving.

Answer 35

False — limited write cycles, small size and easy loss make them poor archival media

Question 36

True or False: EEPROM memory is volatile.

Answer 36

False — EEPROM is non-volatile; data persists without power

Question 37

True or False: Optical drives are generally faster than SSDs.

Answer 37

False — optical drives are significantly slower than both SSDs and HDDs

Question 38

True or False: An M.2 drive supporting both B and M keys can plug into any M.2 slot regardless of key type.

Answer 38

True — a drive with both keys is compatible with either B or M key interfaces

Question 39

True or False: A 3.5 inch hard drive is typically used in laptops.

Answer 39

False — 3.5 inch drives are for desktops; laptops use 2.5 inch drives

Question 40

True or False: SAS is expected to achieve even faster throughputs in future versions.

Answer 40

True

Question 41

Scenario: A desktop is slow and still has a traditional HDD. What is the single most impactful upgrade?

Answer 41

Replace the HDD with an SSD — SSDs are many times faster and will greatly improve overall system throughput

Question 42

Scenario: Building a high-performance laptop needing the fastest possible storage connection. Which interface and protocol?

Answer 42

M.2 interface with NVMe — provides approximately 20 Gb/s by connecting directly to the PCI Express bus

Question 43

Scenario: A server room uses large spinning hard drive arrays and needs the highest throughput for those drives. Which technology?

Answer 43

Serial Attached SCSI (SAS) — provides approximately 22.5 Gb/s compared to SATA's 6 Gb/s

Question 44

Scenario: A technician tries to plug a SATA drive into a SAS backplane but it won't connect. Why?

Answer 44

SAS and SATA connectors are intentionally slightly different to prevent accidental cross-connection

Question 45

Scenario: A user has stored important documents only on a USB flash drive for two years. What risk should they be warned about?

Answer 45

EEPROM has limited write cycles and may stop accepting writes; flash drives are easy to lose — always maintain a backup in a separate location

Question 46

Scenario: A laptop M.2 slot may or may not support NVMe. What should the technician do before buying a drive?

Answer 46

Check the motherboard documentation for the M.2 key type (B, M or both) to confirm NVMe support

Question 47

Scenario: A technician needs to read old DVD-ROM archives but the modern PC has no optical drive. Simplest solution?

Answer 47

Connect an external USB optical drive reader to the system

Question 48

Scenario: A new SSD feels limited in speed and is connected via SATA. What upgrade unlocks its full performance?

Answer 48

Move the SSD to an M.2 NVMe interface — SATA caps at 6 Gb/s while NVMe over M.2 reaches approximately 20 Gb/s

Question 49

Scenario: Comparing two identical hard drives — one at 5400 RPM and one at 7200 RPM. Which is better and why?

Answer 49

The 7200 RPM drive — faster platter rotation reduces latency so data reaches the read/write head sooner