10+ Key Memory & Storage Systems: Crash Course System Design #5
Understanding Computer Memory and Storage
The Basics of RAM and ROM
- RAM (Random Access Memory): Temporary storage that holds data while the computer is running; it is fast but volatile, losing data when powered off.
- ROM (Read-Only Memory): Non-volatile memory that retains data without power, used for essential information like firmware and BIOS.
Types of RAM
- SRAM (Static Random Access Memory): Fast and expensive, utilized in high-speed applications such as CPU caches due to its quick access time.
- DRAM (Dynamic Random Access Memory): Slower and cheaper than SRAM; requires constant refreshing to maintain data integrity.
Variants of DRAM
- Various types of DRAM include FPM, EDO, SDRAM, and DDR SDRAM. Each generation improves speed and efficiency.
- Current common types are DDR variants like DDR4; GDDR is a specialized type optimized for GPUs with faster data transfer rates.
Roles of ROM
- Firmware: Software stored in ROM that manages hardware communication.
- BIOS (Basic Input/Output System): Initial software run at startup responsible for hardware initialization and handover to the operating system.
Exploring Hard Disk Drives vs. Solid State Drives
Hard Disk Drives (HDD)
- HDDs use spinning magnetic disks for data storage; they offer large capacities at lower prices but are slower compared to SSDs.
Solid State Drives (SSD)
- SSDs utilize NAND-based flash memory providing faster access times, reduced power consumption, and greater durability despite higher costs.
Advanced Storage Technologies
NVMe Technology
- NVMe (Non-Volatile Memory Express): A high-performance interface for SSD connections directly to the CPU via PCIe lanes, resulting in lower latency and faster transfer rates compared to SATA-based SSD options.
Portable Storage Solutions
Flash Drives and SD Cards