Computer Memory (RAM)

Computer Memory (RAM)

1. Random Access Memory

   • The contents can be edited
   • The main memory in the computer is made up of RAM.
   • The storage capacity is measured in gigabytes (GB).
   • Computers come with different amount of RAM ranging from 2 GB to 16 GB or more.

2. The Larger amount of RAM

   • The computer can have more programs in the memory at the same time.

3. Volatile Memory

   • Contents are lost when the computer is switched off

4. CPU

   • Views Main memory as a collections of locations arranged in order
   • It can access any location in main memory by specifying its address.
   • It takes less time to access main memory compared to other storage devices like magnetic and optical disk
     • Because main memory is a solid state
       • Solid state means that the storage device in question has no moving parts

5. Types of RAM

   • DRAM
     • Dynamic Random access memory
     • It can be manufactured more cheaply than SRAM.
     • Each location leaks its charge slowly and would eventually lose its content if it wasn't regularily refreshed by electric chare
     • It produces more power than SRAM.
     • During the refresh process, the CPU cant access DRAM, making it slower than SRAM.
   • SRAM
     • Static Random Access Memory
     • It does not have to be refreshed with electric charge
     • It is faster than DRAM as the CPU does not have to wait to access data from SRAM.
     • More expensive than Dram because...
       • The chips produces less power than DRAM.
       • More complex to make than DRAM.
     • 8GB SRAM can't be main memory because...
       • Take too much physical space and be too expensive.
       • It is used in cache memory as a small amount of very fast memory is needed
   • CMOS
     • On-board memory chip
       • Is RAM because the battery keeps the CMOS supplied with power while the computer is switched off
     • Powered by a CMOS battery
       • Inside a computer
         • That stores information such as the system date and time as well as the system hardware settings for your computer
     • Non-volatile
       • The lithium battery provides power to the chip when the computer is switched off
     • Battery should last up to 10 years but the time can vary
       • If the system clock runs slow or the system begins to lose its settings
         • It is a signs that the battery needs replacement