Upgrading and Repairing Upgrading and Repairing PCsPCs

Chapter 3Chapter 3

Processor Overview: ch 3Processor Overview: ch 3

• Brain of the PCBrain of the PC• Intel, AMD, Cyrix, and Alpha are popular Intel, AMD, Cyrix, and Alpha are popular

manufacturersmanufacturers• Speed is measured in MHz (megahertz) Speed is measured in MHz (megahertz)

and soon GHz (Gigahertz)and soon GHz (Gigahertz)• Performance measured by speed (Mhz) Performance measured by speed (Mhz)

and width (bus width)and width (bus width)

Processor SpecificationsProcessor Specifications

• Data BusData Bus– Used to receive and transmit dataUsed to receive and transmit data

• Internal RegistersInternal Registers– Area for processor to calculate dataArea for processor to calculate data

• Memory Address BusMemory Address Bus– Carries addressing information concerning Carries addressing information concerning

where data is being sent or received from where data is being sent or received from RAMRAM

Processor ModesProcessor Modes

• Real ModeReal Mode– 16 bit instructions/use only 1MB of memory16 bit instructions/use only 1MB of memory

• Protected ModeProtected Mode– 32 bit instructions/applications run in 32 bit instructions/applications run in

protected memory spacesprotected memory spaces

• Virtual Real ModeVirtual Real Mode– Used in Windows for backwards Used in Windows for backwards

compatibilitycompatibility

Processor FeaturesProcessor Features

• SMM (System Management Mode)SMM (System Management Mode)– Power Mgmt. Standard used in Power Mgmt. Standard used in

portablesportables

• Superscalar ExecutionSuperscalar Execution– Execute multiple instructions Execute multiple instructions

simultaneously simultaneously

Processor FeaturesProcessor Features

• MMX (Multi Media eXtensions)MMX (Multi Media eXtensions)– Improves video, imaging, and I/O processingImproves video, imaging, and I/O processing

• Dynamic ExecutionDynamic Execution– Anticipates a programs needs before handAnticipates a programs needs before hand

• DIB Architecture (Dual Independent Bus)DIB Architecture (Dual Independent Bus)– Separate busses for memory accessSeparate busses for memory access

Processor FeaturesProcessor Features

• L1 cacheL1 cache– Built into CPUBuilt into CPU– As fast as CPU, 90% success rateAs fast as CPU, 90% success rate

• L2 cacheL2 cache– Previously, always located on motherboardPreviously, always located on motherboard

• Faster than RAM, slower than CPUFaster than RAM, slower than CPU• 90% success rate90% success rate

– Trend: locating on CPUTrend: locating on CPU• Smaller faster cache better than slower Smaller faster cache better than slower

bigger cachebigger cache

Most Common Processor Most Common Processor SocketsSockets

• Socket 7 Socket 7 – Used by Pentium and Pentium MMXUsed by Pentium and Pentium MMX– Still being used by AMD and Cyrix under the Still being used by AMD and Cyrix under the

name Super 7name Super 7

• Slot 1 - Used by Pentium II. Looks like a Slot 1 - Used by Pentium II. Looks like a cartridgecartridge– Cache mounted in slot for faster accessCache mounted in slot for faster access– Not used by any other manufacturerNot used by any other manufacturer