The Motherboard Objectives After completing this section you will Understand the major components on a motherboard including the microprocessor chipset math coprocessor and expansion slots Understand the basic operation of a microprocessor and what issues must be considered when upgrading it Recognize and identify the microprocessor Understand the differences among the various architectures and buses Recognize different expansion slots Recognize an adapter s architecture or bus Microprocessor Overview Microprocessor or processor CPU Central Processing Unit Clones IBM compatibles PC Stands for Personal Computer another name for the microcomputer We will focus on compatibles or non Apple computers because they make up the majority of computers in use today Because Intel and AMD are the microprocessors primarily used in today s computer industry they are the examples covered extensively in this material Microprocessor Basics Bit Either a 1 or 0 All microprocessors use 1s and 0s to calculate or interpret information Byte Eight bits grouped together the letter A looks like 01000001 to the processor Each character on the keyboard appears as one byte or eight bits to the CPU Denoted by the letter B thirty two bytes is 32B Kilobyte Approximately 1 000 bytes 1 024 exactly but rounded off by the industry to the nearest thousand for ease of calculation Shown as K or KB ten kilobytes is shown as 10K or 10KB Megabyte Approximately one million bytes and referenced by M or MB 540 megabytes is shown as 540M or 540MB Gigabyte Approximately 1 billion bytes 1 073 741 824 and written as 1G or 1 GB Microprocessor Basics Motherboard Table 1 Microprocessor Basics Gigahertz GHz Hertz is a measurement of cycles per second or frequency One hertz equals one cycle per second One megahertz 1MHz is equal to one million cycles per second one gigahertz 1GHz is one billion cycles per second For comparison the 8088 microprocessor ran at 4 77 MHz today s CPUs run at over 2 GHz Register size The number of bits processed at one time by the processor Counted in multiples of 8 bits such as 8 16 and 32 bit register size Sometimes referred to as word size by the computer industry Intel s 8086 processor s word size was 16 bits or 2 bytes Most microprocessors today have 64 bit or 128 bit register sizes Bus Electronic lines to move the 1s and 0s inside the computer Microprocessor Basics Internal data bus Moves the 1s and 0s inside the microprocessor In the 8086 there are 16 separate electronic lines each carrying one 1 or one 0 The word size and internal data bus were the same size 16 bit External data bus Used to connect the microprocessor to adapters storage devices and peripherals Also called the external data path these lines connect to ports and expansion slots The Intel 8088 had an 8 bit external data bus Today s CPUs have 64 bit external data paths Today s microprocessors have 64 bit or 128 bit internal data bus lines and external data paths Microprocessor Basics Internal and External Data Buses Motherboard Figure 1 Microprocessor Basics Intel Microprocessors Motherboard Table 2 Microprocessor Basics Pipelines Separate multiple internal buses that operate simultaneously This allows tasks and instructions to be broken down into smaller and more numerous parts which permits the CPU to act on them more quickly and efficiently improving computer performance SEC Single Edge Contact cartridge Used with an Intel Slot 1 connector on Intel s Pentium II microprocessor to reach speeds of 300MHz SEPP Single Edge Processor Package cartridge Similar to the Pentium II SEC and used with the Intel Celeron processor Microprocessor Basics Intel Microprocessors Motherboard Figure 2 Microprocessor Basics Motherboard Figure 3 Microprocessor Basics Intel CPU Sockets and Slots Motherboard Table 3 AMD Processors AMD Advanced Micro Devices Inc Produces a microprocessor similar to the Intel processors Super 7 Socket Redesigned Socket 7 that allows for higher bus speeds 66 to 95 or 100MHz Super 7 motherboards allow higher CPU speeds support for AGP and Ultra DMA hard drives and have advanced power management features Socket A 462 pin PGA socket for the AMD Athlon and Duron CPUs Slot A Used by early AMD Athlon processors similar to Intel Pentium III but they are not interchangeable AMD Processors AMD s Socket A Motherboard Figure 4 AMD Processors AMD Athlon Motherboard Figure 5 AMD Processors AMD CPU Sockets and Slots Motherboard Table 4 MMX SSE and 3DNOW MMX A microprocessor technology from Intel that adds 57 instructions to an Intel processor to help with multimedia and communications software SSE Streaming SIMD Extensions Intel s processor technology that speeds up 3 D applications by allowing instructions to be used by multiple data items There are 50 instructions allowing floating point calculations to occur simultaneously 3DNOW 21 instructions and support for SIMD added to an AMD processor for 3 D applications Processor Speeds and Cooling Microprocessors and math coprocessors come in many speeds and this is measured in gigahertz GHz Hertz is a measurement of cycles per second or frequency One hertz equals one cycle per second One megahertz 1MHz is equal to one million cycles per second one gigahertz 1GHz is one billion cycles per second The faster the microprocessor runs the hotter it gets Many processors now have heat sinks metal bars protruding from the CPU to form a basic radiator or small fans for cooling In many cases today s processors have both Some systems even have multiple fans to prevent damage to the processor and internal components due to the amount of heat being generated Liquid cooling system liquid is circulated through the system including through a heat sink that is mounted on the CPU It allows higher clock speeds and is quieter than a fan Processor Speeds and Cooling Microprocessor Speeds Motherboard Figure 6 Processor Speeds and Cooling Microprocessor Fan and Heat Sink Motherboard Figure 9 Processor Speeds and Cooling Other things to know when determining processor speeds Jumper Small metal connector with a plastic cover used to connect two metal pins together Configuring the jumpers on a motherboard will change the settings on that board Multiplier A number that is multiplied by the bus speed to determine the CPU speed Example 60MHz bus speed x 1 5 multiplier 90MHz CPU Processor Speeds and Cooling CPU with Heat Sink and Fan Motherboard Figure 10 Processor Speeds and Cooling JP1 Jumper Block with Pins 1 and 2