HARDWARE FUNDAMENTALS

WEEK 4

- LE

SSON 1

LEARNING OUTCOMESDefine the term bus

Explain the different bus characteristics

Calculate bus throughput in bps and MB/s

Explain BSB, and FSB

Explain Double Data Rate, Quad Data Rate, and HyperTransport

Define the term expansion bus

Explain the different expansion bus types

Compare VESA versus PCI

Compare PCI versus AGP

Describe different ports (Serial, Parallel, USB, FireWire, IDE, EIDE, SCSI and SATA)

BUS

A collection of wires/tracks that transfer data or power between computer components, typically controlled by a device driver software

internalexternalcomputer to computer

Every component in a computer connects to a bus - even components such as the VDU or printer connect to a bus in some way

BUS CHARACTERISTICS

• Clock speed

• Width

• Bus performance

• Control signals

• Logical and physical connection

• Internal and external

• Serial and parallel

CLOCK SPEED

number of times a bit is sent along the bus

measures how quickly bits move along a bus

WIDTH

number of data bits that can be sent along the bus at once (i.e. 8, 16, 32, 64bits)

BUS PERFORMANCE

Bus throughput number of bytes of data that can be transferred via the bus in one

second

Bus throughput calculation bus clock speed * bus width = bus throughput

CONTROL SIGNALS

• which component the data is for

• where blocks of data start and end

• any other information related to the data being transferred

LOGICAL AND PHYSICAL CONNECTION

Logical connectionOne-to-many (several devices sharing the same set of wires) or point-to-point connection

Physical connectionEach bus defines its set of connectors to physically plug devices, cards or cables together

INTERNAL AND EXTERNAL

Internal bus connects all the internal components of a computer to the motherboard

also referred to as a local / Motherboard bus, because they are intended to connect to local devices

External bus connects external peripherals to the motherboard

SERIAL AND PARALLEL

Serial buses carry data in bit-serial form

Parallel buses carry data words striped across multiple wires problem: crosstalk across multiple wires

BSB AND FSB

BSB

Back Side Bus

The bus that connects the processor to the different levels of cache

Found on the processor chip

FSB

Front Side Bus

The bus that connects the processor to the different hardware components found on the motherboard

IMAGES OF A SOCKET 939 MOTHERBOARD FOR AN AMD ATHLON 64 AND 64 FX PROCESSOR

1/03/10

 

EXPANSION BUS

EXPANSION BUS

A collection of wires and protocols that allows the expansion of a computer by inserting printed circuit boards (expansion boards)

EXPANSION BUS TYPES

PC BusISAMCAEISAVESAPCIAGPPCI Express

PC BUS

• 1981• Developed for the original IBM PC• Used on 8088 and 8086

motherboards • width: 8b• speed: 4.77MHz• throughput: 38.16Mbps 4.77MB/s

ISA

• Industry Standard Architecture• 1984• twice the width of PC bus• PC bus is backwards compatible with ISA• local bus for the Intel 386 CPU• Still today, some motherboards that support

Pentium 4 processors have an ISA expansion bus

• Used on 286, 386, 486, Pentium and some Pentium 4 motherboards

• width: 16b• speed: 8MHz• throughput: 128Mbps 16MB/s

MCA

• Micro-Channel Architecture

• 1987

• IBM introduced MCA to replace ISA, but it never became popular and was soon discontinued

• Twice the width of ISA but not compatible with the ISA or PC bus

• Used on 386 and 486 motherboards

• width: 32b

• speed: 10MHz or 16MHz

• throughput: 320Mbps - 512Mbps 40MB/s - 64MB/s

EISA

• Extended Industry Standard Architecture

• 1988• Used on 486 motherboards• width: 32b• speed: 8.33MHz• throughput: ____266.56Mb/s______ ________33.32__ MB/s

VESA

Video Electronics Standards Associationaka VESA Local Bus (VLB)1992Twice the width of ISAISA and PC bus are backwards compatible

with VESAUsed on 486 motherboardswidth: 32bspeed: 66MHz (maximum)throughput: ___2112_______ Mbps ___264_______ MB/s

PCI 1.0

• Peripheral Components Interconnect• 1992 (1995 with Windows 95)• Supports Plug and Play (PnP)• Used on Pentium motherboards• Transfers data only on one edge of

the clock signal• width: 32b• speed: 33MHz (maximum)• throughput:___1056_______ Mbps___132____ MB/s

PCI 2.0

• PCI 1.0 is backwards compatible• faster and wider than PCI 1.0• width: 64b• speed: 66MHz (maximum)• throughput:_____4224_____ Mbps_____528_____ MB/s

VESA VERSUS PCI

VESA PCI

Maximum of 3 slots Maximum of 8 to 10 slots

Long, ISA and PC bus backwards compatible

Shorter, more compact connector

Developed before PnP Supports PnP

Used only on 486 processors

Used on Pentium class processors

AGP (1 OF 2)

Accelerated Graphics Port1997Intel bus specification providing faster memory

access than PCIGreatly speeds Virtual Reality (VR) and 3D

(Dimensional) rendering and texture mapping than PCI

Developed only for video cardsUsed on Pentium II motherboardsIn its lowest speed mode the throughput is

twice as fast as PCI, plus the benefits of not having to share the bandwidth

Transfers data on two edges of the clock signal

AGP (2 OF 2)

width: 32b

speed: 66MHz

throughput:2,112Mbps264MB/s

Available in four speeds (four specifications), the clock is doubled each time:

x1 264MB/sx2 528MB/sx4 _1,056____ MB/sx8 __2,112___ MB/s

PCI VERSUS AGPPCI AGP

Non-pipelined requests Pipelined requests

Address/data multiplexed Address/data de-multiplexed

Peak throughput in 32b is 132MB/s

Peak throughput in 32b is 264MB/s

Multi-target, multi-master Single-target, single-master

Link to entire system Memory read/write only, no other input/output operations

No priority queues High/low priority queues

PCI EXPRESS (1 OF 2)

• Peripheral Components Interconnect Express (PCIe)

• 2004• Initially named 3GIO (Third Generation

Input/Output)• high speed connection• Used on Pentium 4 motherboards• Uses a packetised protocol (8bit/10bit encoding)• Starting freqency 2.5GHZ, go up to 10 GHZ• Hot plug and hot swappable capability• Power management capabilities

PCI EXPRESS (2 OF 2)

Uses point-to-point connections known as lanes

Each lane on the bus is capable of transferring data in full duplex over two pair of differentially signaled wires called a .

Each lane allows 250 MBps throughput in each direction. Design allows for scalling from 1 to 2, 4, 8, 16 and 32 lane (x16 bus totals 32 lanes)

Four bus types: x1, x4, x8, x16 x1 bus throughput is 250MB/s * 2 = 500MB/s x4 bus throughput is 1GB/s * 2 = 2GB/s x8 bus throughput is 2GB/s * 2 = 4GB/s x16 bus throughput is 4GB/s * 2 = 8GB/s

PCI EXPRESS 2.0

Released 15 January 2007Doubles the bus standard bandwidth of previous version i.e. x16 bus throughput at 8GB/s * 2 = 16GB/s is backwards compatible

Features improvements to the point-to-point data transfer protocol and its software architecture

Intel is expected to release its first chipsets supporting PCIe 2.0 in the second quarter of 2007 with its ‘Bearlake’ family

AMD starts supporting PCIe 2.0 from its RD700 chipset series

NVIDIA has revealed that the MCP72 will be their first PCIe 2.0 equipped chipset

http://en.wikipedia.org/wiki/PCI_Express

PCI Express link performance

PCI Expressversion

Line code

Per lane In a ×16 slot (16-lane)

Raw bit

rate[a]

Bandwidth[a] Raw bit rate[a] Bandwidth[a]

1.0 8b/10b2.5 GT/s

2 Gbit/s250 MB/s

40 GT/s 4 GB/s

2.0 8b/10b 5 GT/s 4 Gbit/s500 MB/s

80 GT/s 8 GB/s

3.0128b/130b

8 GT/s7.877 Gbit/s

984.6 MB/s

128 GT/s

15.754 GB/s

4.0128b/130b

16 GT/s

15.754 Gbit/s

1969.2 MB/s

256 GT/s

31.508 GB/s

a. In each direction.

PCI

BUS TIMELINE

DIFFERENT INPUT / OUTPUT / STORAGE PORTS

SERIAL

• 1 copper wire

• slower

• 1 bit at a time

• Serial protocol

• faster, fewer electrical connections and inherently has no timing skew or crosstalk

PARALLEL

8 copper wires

faster

8 bits at a time

Slower in comparison to Serial packetized protocol

USB• Universal Serial Bus• 127 devices, daisy chained bus designed to eliminate cable

clutter• hub is very important unit, each device can hold another hub for

other devices (PC to PC)• 4 wire cable: 2 wires supply power for devices, other 2 wires

used to send data and commands• PnP and hot swappable• internal and external• In expensive cable which can reach up to 5 meters long (USB

hubs can be daisy chained up to 25m)• USB 1.0 = 1.5Mbps (keyboard mouse), 12Mbps (printer,

monitors , etc)• USB 2.0 = 480Mbps• USB 1.0 is backwards compatible with USB 2.0• USB 3.0 = 5 Gbit/s (625 MB/s)

• A successor standard named USB 3.1 was released in July 2013, providing transfer rates up to 10 Gbit/s (1.25 GB/s, called "SuperSpeed+"

HOT SWAPPING AND HOT PLUGGING

are terms used to separately describe the functions of replacing system components without shutting down the system. Hot swapping describes replacing components without significant interruption to the system, while hot plugging describes the addition of components that would expand the system without significant interruption to the operation of the system.[1]

For hot swapping once the appropriate software is installed on the computer, a user can plug and unplug the component without rebooting. A well-known example of this functionality is the Universal Serial Bus (USB) that allows users to add or remove peripheral components

such as a mouse, keyboard, or printer.

FIREWIRE

• i.Link or IEEE 1394• Different versions of firewire (firewire 400,

firewire 800)• Up to 800mbps• 4.5m cable length• 16 cables can be daisy chained up to 72

meters long• Serial• 63 devices• Hot plug• Internal and external• 4-pin (digital camera) and 6-pin firewire (PC)• Power provided

IDE

• Intelligent / Integrated Device Electronics

• Parallel ATA (Advanced Technology Attachment)

• cheap devices and controllers

• maximum of 2 drives

• only supports hard drives maximum of 528MB capacity

• easy to install and setup

• slow

• internal drives only

• no power provided

EIDE

• Enhanced IDE• Parallel ATA• Used on pentiums• Cheap drives and controllers• Maximum of 2 drives for each of the 2 controllers (4 drives)• 300GB storage capacities• HDD, CD, DVD, zip drives• Easy to install and setup• 40 cable pins (40- 80 wires)• Internal drives only• Ultra/ATA 133 (133MB/s)• Cable 40cm long• Bulky, inflexible, fragile and too short

• Not hot swappable• 4 pin power connector• No power provided

SATA

• Serial ATA (internal) up to 1 meter cable length• Esata (external) up to 2 meter cable length• 7 cable pins (4-7 wires)• One serial drive per port• Point-to-point connection• Connectors are 8mm wide• Cable thinner and more flexible, provides better

airflow• Connectors are more compact• Hot-plug capability• 1.5gbps (150MB/s *8 = 1200 = 1.2gbps + overheads

= 1.5gbps), 3gbps (300MB/s), 6gbps (600MB/s)• 15-pin power connector• Supports 8B/10B encoding• No power provided

SATA- IDE

SCSISmall Computer Systems Interfaceuse on servers and non-Intel PCexpensive drives and controllerssupports 7-15 devicesall types of drives (i.e. hard disks, scanners)hard to install and setupfast for serversexternal drivesup to 12 meter cable length (Ultra-320 SCSI

= 320MB/s)must use terminatorno power provided

SCSI

A SCSI CHAIN

The advantage of SCSI is that several peripherals can be daisy chained to one host adapter, using only one slot in the bus.

RAID

Redundant Array of Independent / Inexpensive Disks

Multiple disks accessed in parallel will give greater throughput than a single disk

Redundant data on multiple disks provides fault tolerance

used in servers or main frames (although can be commonly setup on desktop PCs)

provides higher reliability and/or faster access/performance depending on RAID type

drives in a RAID system are hot swappable for servers and mainframes

RAID appears to the OS as one single logical hard disk

6 standards (RAID 0 to RAID 5) (RAID 1 = mirroring)

although can get different combinations of RAID (RAID 10, RAID 53)

RAID