What is RAM?
- When discussing memory in computers, we typically refer to Random Access
Memory (RAM), not long-term storage like hard drives or
SSDs.
- RAM is temporary, high-speed storage used for executing applications and performing
calculations.
- The computer can only process data that has been loaded into RAM, making it essential for
performance.
- Data is frequently transferred between storage drives (e.g., HDD/SSD) and
RAM for processing.
Memory Technology Evolution
- Memory technology evolves over time, with newer versions offering improved speed and capacity.
- Faster memory generally leads to better overall system performance.
- Memory modules are not universally compatible—each motherboard has specific
requirements.
- Always check motherboard documentation before upgrading or transferring memory.
Memory Modules: DIMM and SO-DIMM
- DIMM (Dual Inline Memory Module) is the standard memory module for desktops.
- Named "dual inline" because it has separate electrical contacts on each side of the module.
- Data is read/written in 64-bit blocks, known as the data width.
- SO-DIMM (Small Outline DIMM) is a smaller version used in laptops and mobile
devices.
- SO-DIMMs are about half the size of standard DIMMs, making them ideal for compact devices.
- Installation is similar for both types—slide into the slot and secure with side locks.
Dynamic Random Access Memory (DRAM)
- RAM chips are a type of Dynamic Random Access Memory (DRAM).
- "Random access" means any data can be accessed instantly, unlike sequential storage (e.g., magnetic
tape).
- Modern computers use Synchronous DRAM (SDRAM), which synchronizes with the system
clock for consistent data transfer.
Double Data Rate (DDR) Memory
- Older memory used Single Data Rate (SDR), transferring one bit per clock cycle.
- Double Data Rate (DDR) memory transfers data on both the rising and falling edges
of the clock cycle, effectively doubling speed.
- DDR versions (e.g., DDR3, DDR4, DDR5) are not backward compatible due to physical
and electrical differences.
- Each DDR version improves speed, capacity, and efficiency over its predecessor.
- Memory modules have key notches to prevent installation in incompatible slots.