Addressing Memory

(OBJ 3.3)

Addressing Memory - processor reaching files inside RAM

• Cache - high speed memory; fastest form of memory but holds less data than RAM
• Storage - permanent mass storage device; holds more data but slower than cache
• Disk Cache - pulls files from disc into memory and replaces old file
• RAM uses an electronic system that can access RAM with instant speed; within billionths of a second
• Hard Disk is considered very slow and operates in milliseconds

Between Memory and CPU sits a Memory Controller, and between Memory Controller and CPU is a Bus

Bus - a pathway for us to transfer data

• Data Pathway - to send and receive information
• Address Pathway - to determine where the data is located

Address space limits:

• Using a 32-bit (x86) CPU, there’s approximately 4 billion address locations which = 4 GB of data maximum
• Using a 64-bit (x64) CPU, there’s roughly 184 quintillion address locations = 16EB of data, significantly more than 4GB of RAM

For most modern systems, 64-bit CPUs are the way to go