Hardware, Software, and Peripherals Memory and Storage Devices

Memory and Storage Devices Module of Hardware, Software, and Peripherals

This type of memory loses content when power is off (e.g., RAM)

Volatile Memory

This type of memory retains content without power (e.g., ROM, Flash Memory)

Non-Volatile memory

Year, Prefetch (Bits), Data Rate (MT/s), Transfer Rate (GB/s), and Voltage (V) of DDR1

2000, 2, 200–400, 1.6–3.2, 2.5

Year, Prefetch (Bits), Data Rate (MT/s), Transfer Rate (GB/s), and Voltage (V) of DDR2

2003, 4, 400–1066, 3.2–8.5, 1.8

Year, Prefetch (Bits), Data Rate (MT/s), Transfer Rate (GB/s), and Voltage (V) of DDR3

2007, 8, 800–2133, 6.4–17.0, 1.5

Year, Prefetch (Bits), Data Rate (MT/s), Transfer Rate (GB/s), and Voltage (V) of DDR4

2014, 8, 1600–3200, 12.8–25.6, 1.2

Year, Prefetch (Bits), Data Rate (MT/s), Transfer Rate (GB/s), and Voltage (V) of DDR5

2020, 16, 3200–6400, 25.6– 51.2, 1.1

This memory technology works in sync with CPU clock

SDRAM

What does SDRAM stand for?

Synchronous DRAM

Less common, high-speed memory technology used in specific systems

RDRAM

What does RDRAM stand for?

Rambus DRAM

Common form factor for desktop computers\nEvolution from DDR1 to DDR5

DDR DIMMs

Compact version of DIMM, used in laptops and smaller devices

SO-DIMM

Standard consumer-grade memory

UDIMM

What does UDIMM stand for?

Unbuffered DIMM

Commonly used in servers for higher reliability

RDIMM

What does RDIMM stand for?

Registered DIMM

High-speed memory used with RIMM (Rambus Inline Memory Module)\nInitially developed for high-performance computing but now obsolete\nMostly replaced by DDR memory

RDRAM (Rambus Memory)

High-speed memory located between the CPU and main memory, improves system performance by reducing access time to frequently used data

Cache Memory

Level of cache that is the smallest and fastest, located directly on CPU

L1 Cache

Level of cache that is larger but slower, on CPU or motherboard

L2 Cache

Level of cache that is the shared cache used in multi-core processors

L3 Cache

Type of flash memory that is commonly used in SSDs, USB drives

NAND Flash

Type of flash memory that is used for faster read speeds, but less common

NOR Flash

These drives store data on spinning magnetic platters with read/write heads that move across the disk surface.

Magnetic Hard Drive

These drives use flash memory to store data without moving parts. These are faster, more durable, and more power-efficient than HDDs. They have varying speeds based on the type of interface they use (SATA, NVMe), with NVMe SSDs offering much higher data transfer rates (up to several GB/s).

Solid State Drive

These defines how the drive communicates with the computer’s motherboard

Interfaces

What do NVMe drives use?

PCIe lanes

Where are NVMe SSDs inserted directly in?

Motherboard's M.2 slot

What are common interfaces examples?

SATA (Serial ATA), NVMe (Non-Volatile Memory Express), and SAS (Serial Attached SCSI)

This is the process of dividing a drive into sections (partitions) that the operating system can manage independently. This allows multiple file systems or operating systems to be installed on one drive, or to better organize data.

Partitioning

What are common types of partitions?

Primary, Extended, and Logical partitions

This prepares a partition to store files by setting up a file system. It involves writing a file system (like NTFS for Windows, HFS+ for Mac, or EXT4 for Linux) to a partition, enabling it to store and manage files.

Formatting

A utility for managing drives, partitions, and file systems. In windows, it allows users to create, delete, format, or resize partitions, and assign drive letters.

Disk Management

Refers to a system's ability to continue operating in the event of a hardware failure.

Fault Tolerance

An example of a technique a hard drives uses to provide redundancy, so data isn't lost if a drive fails?

RAID

What does RAID stand for?

Redundant Array of Independent Disks

This splits data across multiple drives for performance (no redundancy)

RAID 0

This mirrors data for redundancy

RAID 1

This uses both striping and parity for a balance between performance and redundancy.

RAID 5

These drives include USB flash drives, external HDDs/SSDs, and optical media (CDs, DVDs). These are portable storage devices used for transferring files between systems or providing additional storage without internal installation.

Removable Drive Storage

A temporary storage area (cache) for frequently accessed data. It improves performance by reducing the need to access the slower main storage medium (HDD or SSD) for frequently used data. It’s common in hybrid drives (SSHDs), where an SSD cache is combined with an HDD.

Disk Caching

This is when the operating system uses part of the hard drive as if it were RAM. It expands the amount of "usable" memory by using disk space, but is much slower than actual RAM. It helps prevent system crashes when physical memory (RAM) is exhausted by offloading less-used data to the drive.

Virtual Memory