2. RAM Overview
• RAM stands for Random Access Memory. It gets
the word "random" because information can be
accessed in non-sequential order. Though the
data itself is stored together, it could be
anywhere in the "container" or amount of RAM
available. RAM is measured in "bits", and 8 bits
equals 1 byte. A kilobyte equals 1024 bits, and a
megabyte equals 1024 kilobytes.
3. Two Main Form of
RAM
DRAM
SRAM (Dynamic
(Static Ram) Ram)
4. SRAM (Static Ram)
• Static RAM is a type of RAM that holds its data
without external refresh, for as long as power is
supplied to the circuit. This is contrasted to
dynamic RAM (DRAM), which must be
refreshed many times per second in order to
hold its data contents. SRAMs are used for
specific applications within the PC, where their
strengths outweigh their weaknesses compared
to DRAM:
5. • Simplicity: SRAMs don't require external refresh
circuitry or other work in order for them to keep
their data intact.
• Speed: SRAM is faster than DRAM.
• Compared to DRAM, SRAM is more power-
efficient when idle.
• SRAM is several times more expensive than
DRAM.
6. DRAM (Dynamic Ram)
• Dynamic RAM is the standard computer
memory of the vast majority of modern desktop
computers. It is a volatile memory that needs to
be refreshed with voltage regularly, otherwise it
loses the information stored on it. Dynamic
RAM is also referred to as DRAM. Volatile
means that it loses the information stored on it
as soon as power is withdrawn.
7. • Dynamic RAM is referred to by its size and
speed. For example, the packaging or description
of the memory module might list 1066 Mhz 1 Gb
DRAM. The 1066 Mhz is the speed at which a
computer can read and write to the memory, and
the higher number the better. The 1 Gb is the
usable space on the chip; in this example, the
chip can store 1 gigabyte of information on it
while it has power. There are several different
types of DRAM.
• Example of DRAM is DIMM, SO-DIMM and
DDR Memory Sticks.
8. Types of RAM Memory Module
•1
• Computer memory has a big effect on system
performance. Pictured above is SIMM memory, or
single in-line memory module, which is a type of
RAM memory module.
9. •2
• DIMM, or dual in-line memory module, has a
64-bit path to memory chips, whereas the SIMM
has only a 32-bit.
10. •3
• SO-DIMM, or small outline dual in-line memory
module, is made with integrated circuits and is
about half the size of DIMM modules