adminVOLATILE MEMORY
Volatile memory is a type of computer memory that requires continuous electrical power to retain stored information or data.
There are several types of volatile memory and they are; DRAM, SRAM, VRAM, cache memory, registers and flash based pseudo-volatile memory.
Dynamic random access memory (DRAM) stores each bit as an electrical charge in a tiny capacitor paired with a transistor. Since capacitors leak, DRAMs must be refreshed thousands of times per second to maintain data integrity.
Static random access memory (SRAM) uses a bi-stable latch made of 4 to 6 transistors to store each bit, no capacitor; no refresh needed and stored data holds as long as power is applied.
Synchronous dynamic RAM (SDRAM) is an evolution of DRAM that synchronizes with the system clock, enabling more predictable and pipelined data transfers.
Video RAM (VRAM) is a specialized DRAM optimized for graphics workloads. It uses a very wide memory bus (256-512 bits) to enable massive parallel data throughput needed for rendering.
Cache memory is a multiple tier of SDRAM based memory embedded directly on the CPU die, acting as ultra-fast staging areas between registers and main DRAM.
Registers is the fastest and smallest form of volatile storage, located directly inside the CPUs execution units. It stores operands and results of arithmetic/logic operations.
Flash-based pseudo volatile memory is an emerging hybrid memory that blurs the line between volatile and non-volatile memory.
The advantages of volatile memory are; they are fast and suitable for high speed operations. They have a high band width thus are able to handle multiple data transfers.
The disadvantages of volatile memory are; loss of power results in data loss, therefore they need constant power to operate satisfactorily. They have a limited storage capacity compared to non-volatile memory storage.
Volatile memory storage find application in the following; computing as main memory such as DRAM, CPU caches, SRAM etc. they are embedded in systems that requires speed, such as SRAM. They are also suitable in networking operations as high speed buffers.
The future of volatile memory depends on the advances and development of the following technologies; emerging technologies such as MRAM (magnetic RAM) etc. for faster, lower power alternatives. Advanced performance of volatile memory with higher speeds, densities in DRAM/SRAM is going to be the norm of the future.
SOURCES:
- High speed memory systems by Alan F. Hamidi.
- DRAM system design edited by Brent Keeth.
- Memory systems by Bruce Jacob, Spencer W. Ng and David T. Wang.
- CMOS VLSI Design by Neil H.E Weste and David Harris.
- Digital integrated circuits by Jan M. Rabaey, Anantha Chandrakasan and Borivoje Nikolic.
