Dynamic RAM

Definition

Dynamic RAM (DRAM) is a type of volatile memory that stores each bit of data in a separate capacitor within an integrated circuit. Unlike static RAM (SRAM), DRAM needs to be refreshed thousands of times per second to maintain the stored information, making it essential for computer memory applications where large amounts of data need to be accessed quickly and efficiently.

5 Must Know Facts For Your Next Test

1. DRAM is widely used in computers and smartphones due to its ability to provide high-density storage at a lower cost compared to SRAM.
2. Each DRAM cell consists of a transistor and a capacitor; the capacitor holds the electrical charge representing data, but this charge leaks over time, necessitating constant refreshing.
3. The refresh cycle for DRAM typically occurs every 64 milliseconds, during which the data is rewritten to maintain integrity.
4. While DRAM is slower than SRAM, its higher density and cost-effectiveness make it suitable for main memory in computers.
5. There are several types of DRAM, including SDRAM, DDR SDRAM, and DRR2 SDRAM, each offering different performance characteristics and speed improvements.

Review Questions

• How does the structure of a dynamic RAM cell contribute to its need for constant refreshing?
  • A dynamic RAM cell consists of a transistor and a capacitor, where the capacitor stores the electrical charge that represents a bit of data. However, over time, the charge in the capacitor leaks away due to its inherent characteristics. This leakage means that the information cannot be held indefinitely, requiring the system to refresh the stored data periodically to prevent loss of information.
• Discuss the advantages and disadvantages of using dynamic RAM compared to static RAM in computer systems.
  • Dynamic RAM offers advantages such as higher storage density and lower manufacturing costs, making it suitable for large memory requirements in devices like computers and smartphones. However, it has disadvantages including slower access times and the need for regular refreshing to maintain data integrity. In contrast, static RAM provides faster access speeds and does not require refreshing, but it is more expensive and less dense than DRAM, which limits its use in applications requiring large amounts of memory.
• Evaluate how advancements in dynamic RAM technology have impacted overall computer performance and capabilities.
  • Advancements in dynamic RAM technology have significantly improved computer performance by increasing memory speeds, capacities, and efficiency. Innovations like DDR (Double Data Rate) technology have allowed DRAM to transmit data on both edges of the clock signal, effectively doubling its data transfer rate without increasing frequency. This has enabled computers to handle more demanding applications such as gaming and data processing efficiently. Additionally, as DRAM has become more cost-effective, it has facilitated the widespread adoption of high-capacity memory configurations in consumer electronics, enhancing overall computing capabilities.

Related terms

Static RAM:

A type of RAM that holds data in a static state as long as power is supplied, requiring no refresh cycles unlike DRAM.

Volatile Memory: Memory that requires power to maintain the stored information; once power is lost, the data is erased.

Memory Cell: The basic unit of storage in a memory device, which can store one bit of information in DRAM using a capacitor and a transistor.