Dynamic Random Access Memory (DRAM).
                     DYNAMIC 
RANDOM-
ACCESS 
MEMORY 
(DRAM)
Introductio
n
• Dynamic random access memory (DRAM) is 
a type of semiconductor memory that is 
typically used for the data or program code 
needed by a computer processor to 
function.
Source: searchstorage.techtarget.com
How does 
DRAM 
work?
• The memory cells will work with other 
circuits that can be used to identify rows 
and columns, track the refresh process, 
instruct a cell whether to accept a charge 
and read or restore data from a cell.
Source: 
searchstorage.techtarget.com
Memory 
choices 
• DRAM is one option of semiconductor memory that a 
system designer can use when building a computer. 
• Alternative memory choices include static RAM 
(SRAM), electrically erasable programmable read-only 
memory (EEPROM), NOR flash and NAND flash.
Source: 
searchstorage.techtarget.com
Types of 
DRAM
• Synchronous DRAM (SDRAM): This allows the CPU to 
perform more instructions at a time.
• Rambus DRAM (RDRAM): was more widely used in the early 
2000s for graphics cards.
• Double Data Rate SDRAM (DDR SDRAM) almost doubles the 
bandwidth in data rate of SDRAM by using double pinning.
Source: searchstorage.techtarget.com
Types of 
DRAM 
cont.
• Fast page mode DRAM (FPM DRAM) gives higher 
performance than other DRAM types through focusing 
on fast page access.
• Extended data out DRAM (EDO DRAM) improves the 
time to read from memory on microprocessors, such as 
the Intel Pentium.
Source: 
searchstorage.techtarget.com
Types of 
DRAM 
packages
• There are two main types of DRAM 
packaging: single inline memory module 
(SIMM) and dual inline memory module 
(DIMM).
Source: 
searchstorage.techtarget.com
Integrated 
circuit 
architecture
s
• Unbuffered DIMMs (UDIMMs) are commonly used on 
desktops and laptops. These cost less and run faster 
but are less stable.
• Registered DIMMs (RDIMMs) are commonly used with 
servers. These are more stable and reduce strain on a 
CPUs memory controller.
Source: 
searchstorage.techtarget.com
Advantage
s
• Its design is simple, only requiring one transistor.
• The cost is low in comparison to alternative types of memory 
such as SRAM.
• It provides higher density levels.
• More data can be stored using DRAM.
• Memory can be refreshed and deleted while a program is 
running.
Source: 
searchstorage.techtarget.com
Disadvantage
s
• Memory is Volatile.
• Power consumption is high relative to other options.
• Manufacturing is complex.
• Data in storage cells needs to be refreshed.
• It is slower than SRAM.
Source: 
searchstorage.techtarget.com
History
• One of the first uses of DRAM was in a Toshiba 
calculator in 1965 using a capacitive form of 
DRAM that was made from bipolar memory cells. 
• That same year, IBM created a 16-bit silicon 
memory chip. 
Source: 
searchstorage.techtarget.com