FC Hardware & Software Week 2 Motherboards and Processors lA primer – bits and bytes lThe hardware at the core of the computer lA history lesson lPerspectives on modern systems

FC Hardware & Software Week 2 Introduction or refresher lBits and Bytes lA bit (symbol “b”) is a single on/off switch, 2 states (value 0 or 1) lA byte (“B”) is a group of 8 bits – one letter/character (range ) lWhy 8 bits? Why not 7 bits for a range of ? lBytes are the basis of computer data storage

FC Hardware & Software Week 2 Introduction or refresher lNetwork speed – often shown in shorthand l“Fast Ethernet cards allow 100 Mbps data transfer…” lIs this saying 100 megabits per second or 100 megabytes per second? lIt’s a difference of a factor of eight, so you had better be sure! lThe information transfer rate is loosely known as “bandwidth” lWi-fi wireless networking is often quoted as having a “speed” or “bandwidth” of 54Mbps (IEEE g standard) lThis gives an absolute maximum of about 6 megabytes per second

FC Hardware & Software Week 2 Introduction or refresher lSizes – Memory (but usually not storage…) lKilo – one thousand (or 1024, closest binary number) lMega – one million (or 1024*1024 in binary) lGiga – one billion (1024*1024*1024) lSo one Megabyte (1MB) of memory has 1,048,576 bytes lBut one Megabit (1Mb) is only 131,072 bytes (=128KB) lSpeeds – “xyz per second” is common in computing lThings “per second” = Hz = Hertz (after George Hertz, scientist) lOne megahertz is 1MHz, one million times per second lOne gigahertz is 1GHz, one billion times per second

FC Hardware & Software Week 2 Introduction to Motherboards lA motherboard is also known as a mainboard or a “mobo” in web slang lMotherboard designs have changed over the years to keep up with new developments lUpdates to the system bus architecture (structure) lChanges in CPU (Central Processing Unit) speed lIntegration of system devices lSound, LAN, Video, USB, IDE/PATA, SATA, FireWire… lNow appearing: Bluetooth, WiFi, USB3, eSATA

FC Hardware & Software Week 2 The PC/AT lOriginal IBM PC/AT (1984) l6MHz chip, rapidly upgraded to 8MHz l16-bit CPU (modern ones are 64-bit) l24-bit address bus (max of 16MB RAM) lCurrent computers are millions of times faster and have thousands of times more memory

FC Hardware & Software Week 2 lA typical server-style “tower” case showing the motherboard lLots of spaces for other devices lExamples: lBlu-Ray/DVD drives lSSDs lControl panels

FC Hardware & Software Week 2 Fast PC/AT motherboards lLater (about 1987) the i386 became available, with a 32-bit data bus lIt could run faster than the normal type of RAM! lThis lead to a problematic choice lEither run the (expensive) CPU as slowly as the RAM lOr decouple the RAM and CPU clocks so they are no longer synchronised in a simple 1:1 relationship (hard)

FC Hardware & Software Week 2 The Chipset – Northbridge, Southbridge lChipset uses two physicals chips: Northbridge and Southbridge lNorthbridge lMemory controller hub – buffers link from CPU to RAM lCore chipset that handles the communication between CPU, RAM, PCI-E and South Bridge lSouthbridge lChipset that handles the communication between North Bridge, PCI and other I/O devices such as USB, Firewire and Gigabit Ethernet

FC Hardware & Software Week 2

FC Hardware & Software Week 2 Diagram lThe two “glue” chips have very different characteristics lThe northbridge runs very fast (CPU speed) lThe southbridge doesn’t run so fast as it handles relatively slow connections

FC Hardware & Software Week 2 Modern systems - common figures lThe ISA expansion bus [8.33MHz] vanished years ago, good for 16Mbps lThe PCI expansion bus ran at 66MHz for a total of about 1Gbps (one gigabit per second) lThe basic PCI-e expansion bus runs at 5Gbps per lane with up to 32 lanes per device, maximum total of 160Gbps lPCI-e is 10,000 times faster than the old ISA bus

FC Hardware & Software Week 2 Processor Characteristics lSocket type – how the CPU plugs into the motherboard lClock speed lFront Side Bus (FSB) - Connection speed between the processor and the chipset lCache sizes, usually 2 or 3 levels of caching lNumber of cores - multi-core helps to ensure that the system remains more responsive even when the processor load is high

FC Hardware & Software Week 2

FC Hardware & Software Week 2 Multi-core processors lMany CPU types are available as multi-core processors

FC Hardware & Software Week 2 Summary lWe have discussed the basics of the motherboard lAnd a little of the history of changes lWe have introduced many terms relating to processors lAnd discussed some modern developments lKey ideas – continual change, speed increases