Transcript Slide 1

Dynamic random
access memory
 Main form of
memory in personal
computers and
game consuls
 Stores each bit of
data in a separate
capacitor within an
integrated circuit

Capacitor can be
either charged or
discharged
 Called dynamic
memory because if
capacitors must be
periodically charged
 If not charged the
information stored in
the capacitors will
eventually be lost

Type of memory used by the CPU
 Each chip holds rows and columns of data
 A DRAM chip that holds 1,048,576 rows and
8 columns would be 1 M x 8 chip

› “M” means megabyte
Originally RAM came in one bit wide sticks
 Now RAM is available in 32-bit and 64-bit
sticks


Structural simplicity
› Only one transistor and one capacitor per
bit
 SRAM has sic transistors
Inexpensive to manufacture
 Small in size
 Can hold larger amounts of information

Loses data when power is removed
 Because data needs to be refreshed it is
slower than SRAM

Static random access memory
 Memory is lost once the power is lost
 Typically find that SRAM is used in:

› cache memory,
› hard drive buffers and in
› other electronics such as children's toys
› Electronic games
Does not loses
data when
powered down
 Date does not
need to be
continuously
refreshed
 Faster then DRAM

Expensive to manufacture
 Larger than DRAM

Synchronous dynamic random access
memory
 Because it is synchronous it is tied to the
system clock
 Allows for higher transfer rates with
interfaces possible
 Has to wait for a clock signal before it
can respond to control inputs and
synchronize with the computer

Introduced in 1996 on a dual inline
memory module stick (DIMM)
 Had varying number of pins
 DIMM slots that stored the memory
referred to as “banks”

Allows computers to run at higher mega
hertz
 Extremely protective of data bits that are
stored into the computer

› This means it will not allow any corrupt
material to be stored in it's drives.

Uses pipelining
› that allows more then one command to be
accept at one time

Not good at
checking to ensure
that electrons in the
computer system are
working properly
› This means it needs to
be constantly
refreshed to ensure
that no information is
not lost
Leader in the computer memory industry
 Develops and licenses high-performance
memory logic and circuit design
technology and provides licensees with
product design
 Created RDRAM

Developed for the
Pentium 4 by
Rambus
 Can handle speeds
up to 800 MHz
 Not well accepted
by the industry
because of high
cost and
production delays


Came in two sizes
› 184-pin (desktops)
› 160-pin (laptops)
Had speed ratings of 600 MHz, 700
MHz,800 MHz, or 1066 MHz
 Had to be installed in pairs because it
alternated between two stick to increase
speed

All slots on motherboard had to be
populated
 Roadblocks faced by RDRAM

› Technology was owned entirely by Rambus
› Expensive
› Rambus and Intel made a closed deal and
RDRAM only worked on Pentium 4 systems
using Intel
Double data rate
 Same principle as RDRAM

› Doubled speed by making two processes for
every clock cycle
Cost only slightly more than regular
SDRAM
 184-pin for desktops
 172-pin or 200 pin for laptops

Sticks are notched so that the wrong
stick can not accidentally be placed in
the wrong slot
 Eventually became adopted as the
standard system RAM
 In 2003 Intel ceased producing for
RDRAM and adopted SDRAM
 Fastest version ran at 4.8 gigabytes per
second

Successor to DDR
 Runs faster than
DDR by clockdoubling the
input/output circuits
 Uses less power
 Uses 240-pin DIMM
which is not
compatible with
DDR

Newest in line of DDR
 More efficient architecture
 30 percent lower power consumption
 Uses a 240-pin DIMM, which is slotted
differentially which prevents users from
installing the wrong ram
 Double the buffer of DDR2 from 4 to 8
bits


Extending memory
profile (xmp)
› Enables RAM to be
overclocked

Triple-channel
memory
› Works like dual
channel but uses
three sticks instead
of two
Double data rate
 Neither forwards or backwards
compatible
 Double data rate means that DDR can
achieve nearly twice the bandwidth of a
single data rate (SDR) SDRAM running at
the same clock frequency, due to this
double pumping.

DDR1

http://www.youtube.com/watch?v=mZA
Q4Y0tjts&feature=related
Single sided have chips on only one side
of the sick
 Double sided have chips on both sides of
the stick
 Majority of sticks are single sided
 Some motherboards are not compatible
with double sided ram

The delays incurred when a computer tries
to access data from the stick of RAM
 The latency number reflects how many
clicks of the system clock it takes before the
RAM responds
 Sticks with lower latency are “faster”
because they have smaller delays
 One stick with lower latency may cost far
more than a the same stick with a higher
latency

Parity RAM was the
first form of error
detecting RAM
 Uses for computers
that must be precise
all the time
 On occasion there
will be an error,
parity RAM detects
the error

Error correction code
 Detects any time a single bit is incorrect
 It fixes any errors on the fly
 ECC RAM is slower than non-ECC RAM
because of the error checking
 Non- ECC RAM does not do error
checking

Dual channel is faster and allows for
more DIMMs
 Dual channel means that you have two
channels/pathways for your CPU to
access your RAM r
 Single channel means there is only one
channel
 More channels allows for more data to
be transferred which results in more
speed


http://www.youtube.com/watch?v=pe
mQxhE7Jhk

The following should automatically
configure, or only need their attached
installed CD to configure
› Keyboard
› Bar code reader
› Multimedia
› Mouse

If will not configure you may need to
download a driver

Uses some sort of physical characteristic
to identify the user, such as
› Face
› Eye
› Fingerprint
› Handprint

Free face recognition software:
› http://www.youtube.com/watch?v=hUc_2O
R7zQ8

A touch screen allows the user to
physically touch the screen to open,
close and move through an application

http://www.youtube.com/watch?v=6jho
WsHwU7w&feature=related





The KVM Switch allows the user to access
different computers using a single monitor,
keyboard, and mouse.
KVM stands for Keyboard, Video, and
Mouse
When installing turn off all computers that
will be connected.
Connect all computers to the switch then
turn back on the computers.
Windows should recognize the new devices
and automatically install them.
http://www.youtube.com/watch?v=E4PI
DZrBGzQ
 http://www.youtube.com/watch?v=rTwxXHswbE
