Communication Interfaces and Data Storage

These flashcards cover essential terms and definitions related to communication interfaces and data storage, including HDDs, SSDs, RAID configurations, and troubleshooting strategies.

NVMe

High‑speed interface made for solid‑state drives; connects through PCIe lanes; speeds up to 7000 megabytes per second; ideal for gaming, video editing, and large data transfers.

SATA

Older interface originally for hard drives; still used with some SSDs; SATA III supports 600 megabytes per second; slower than NVMe but faster than HDDs; good for everyday computing.

eSATA

External version of SATA for connecting external storage; same speeds as SATA III; uses rugged connectors; less common today due to USB and Thunderbolt.

PCIe

General‑purpose high‑speed interface; used for GPUs, NVMe SSDs, and expansion cards; available in x1, x4, x8, x16 lanes; PCIe 5.0 delivers 4 gigabytes per second per lane.

SAS

Enterprise‑grade interface; faster and more reliable than SATA; supports full‑duplex (read/write simultaneously); maintains performance under heavy workloads.

HDD

Traditional magnetic storage using spinning platters and an actuator arm; common sizes: 3.5‑inch (desktop) and 2.5‑inch (laptop).

HDD Spindle Speed – 5400 RPM

Common in laptops; uses less power; slower read/write performance.

HDD Spindle Speed – 7200 RPM

Standard for desktops; balanced speed and efficiency.

HDD Spindle Speed – 10000 RPM

Used in high‑performance systems like gaming and media production.

SSD

Uses flash memory; faster, more durable, and silent compared to HDDs.

NVMe SSD

Fastest SSD type; uses PCIe lanes; speeds up to 7000 megabytes per second.

SATA SSD

More affordable but slower; around 600 megabytes per second.

SAS SSD

Enterprise‑focused SSDs using SAS interface.

M.2 Drive

Small SSD form factor; varies in length/width; slides directly into motherboard slot; may use SATA or NVMe depending on system.

mSATA Drive

Older SSD form factor used in legacy laptops.

RAID

Combines multiple drives into one logical unit for performance, redundancy, or both.

RAID 0

Splits data evenly across drives for speed; requires at least two drives; offers no redundancy — if one drive fails, all data is lost.

RAID 1

Writes identical data to two drives; excellent redundancy; improved read speeds; write speed same as a single disk.

RAID 5

Requires at least three drives; uses one drive’s worth of parity; can survive one drive failure; good read speeds, decent write speeds; strong balance of performance and redundancy.

RAID 6

Requires at least four drives; can survive two drive failures; slower writes due to extra parity; uses two drives’ worth of parity.

RAID 10

Requires at least four drives; pairs are mirrored, then striped; excellent performance and fault tolerance; uses 50% of total capacity.

Flash Drive

USB‑based removable storage; capacities from a few GB to 1TB+.

Memory Cards

Includes SD, microSD, and CompactFlash; used in cameras and mobile devices.

Optical Drive

Reads/writes data using lasers; includes CDs (~700MB), DVDs (up to 8.5GB dual‑layer), and Blu‑ray (25GB or 50GB).

LED Indicator – Signs

Red/amber lights indicate problems; no light indicates power issue.

LED Indicator – Fix

Check LED status, verify power, consult manufacturer documentation.

Strange Noises – Signs

Indicates mechanical failure.

Strange Noises – Fix

Power off system, run diagnostics, replace drive, perform data recovery.

Bootable Device Not Found – Signs

Undetected drive, wrong boot order, loose cables, corrupted boot sector.

Bootable Device Not Found – Fix

Check BIOS/UEFI detection, correct boot order, reseat cables, use recovery tools.

Data Loss/Corruption – Signs

Power failures, file system issues, malware.

Data Loss/Corruption – Fix

Scan/repair file system, check for malware, restore from backup.

RAID Failure

One or more drives stop functioning; RAID 1/5/6/10 can rebuild; RAID 0 loses all data unless backed up.

S.M.A.R.T. Failure

Indicates potential hardware issues; back up data immediately and replace drive.

Slow Read/Write Speeds – Signs

HDD fragmentation, SSD write cycle limits, low RAM causing paging.

Slow Read/Write Speeds – Fix

Defragment HDDs, enable SSD optimization, upgrade RAM, replace failing drives.

Drive Not Recognized – Signs

Uninitialized, improperly formatted, or connection issue.

Drive Not Recognized – Fix

Initialize/format drive, check connections, test different cable/port.

Missing RAID Arrays – Signs

Controller misconfiguration or failure.

Missing RAID Arrays – Fix

Verify controller settings, review logs, check power, reconfigure controller.