3.3 - Storage devices: SSD, NVMe and HDD
CompTIA A+ Core 1 objective 3.3 covers storage devices and interfaces. An NVMe (PCIe) M.2 SSD offers the highest throughput for an OS drive because NVMe uses PCIe lanes directly, far faster than SATA. M.2 slots can be keyed - a B+M keyed slot accepts both SATA and NVMe M.2 drives, which matters for compatibility. Compared with a traditional spinning hard drive, an SSD has no moving parts, so it is more shock-resistant, and it offers much faster access times. You should match a performance or compatibility need to the right drive or interface. Expect scenario questions that describe a speed requirement, an M.2 keying question or an SSD-versus-HDD comparison and ask which is correct. Interface dictates speed, so NVMe over PCIe beats SATA whenever raw throughput matters.
Fastest OS drive = NVMe (PCIe) M.2 SSD. B+M keyed M.2 = accepts SATA and NVMe. SSD vs HDD = no moving parts (shock-resistant) + faster access.
Practice questions
1. Which interface connects internal 2.5"/3.5" SATA drives for DATA?
- A 15-pin Molex plug
- A SATA data cable (7-pin) (correct answer)
- A PCIe x16 slot
- An RJ45 network jack
The 7-pin SATA data cable carries data; the separate 15-pin SATA power cable supplies power.
2. Which storage interface offers the highest throughput for an OS drive?
- SATA III SSD
- NVMe (PCIe) M.2 SSD (correct answer)
- 5400 RPM HDD
- USB 2.0 flash drive
NVMe SSDs use PCIe lanes and are far faster than SATA (which caps ~600 MB/s) or spinning HDDs.
3. Which TWO are advantages of an SSD over a traditional HDD? (Choose two.)
- No moving parts (more shock-resistant) (correct answer)
- Higher maximum capacity per dollar
- Faster access times (correct answer)
- Requires defragmentation
SSDs have no moving parts and much faster access. HDDs still win on cost per TB; SSDs should NOT be defragmented.
4. Which RAID level mirrors data across two drives for redundancy with no striping?
- RAID 0
- RAID 5
- RAID 1 (correct answer)
- RAID 6
RAID 1 mirrors identical data to two drives; if one fails, the other has a full copy.
5. Which technique copies an entire drive (OS + data) to a new SSD so the PC boots identically?
- Disk defragmentation
- Drive cloning or imaging (correct answer)
- Quick disk formatting
- File compression
Cloning copies the whole drive (partitions, OS, data) to a new disk so it boots the same — common for SSD upgrades.
6. Which optical disc holds the most data?
- A CD (700 MB)
- A DVD (~5 GB)
- A Blu-ray disc (correct answer)
- A floppy disk
Blu-ray (~25-50 GB) holds far more than DVD (~4.7-8.5 GB) or CD (~700 MB).