Upgrading and Repairing PCs Chapter 3

Processor Overview: ch 3 Brain of the PC Intel, AMD, Cyrix, and Alpha are popular manufacturers Speed is measured in MHz (megahertz) and soon GHz (Gigahertz) Performance measured by speed (Mhz) and width (bus width)

Processor Specifications Data Bus Used to receive and transmit data Internal Registers Area for processor to calculate data Memory Address Bus Carries addressing information concerning where data is being sent or received from RAM

Processor Modes Real Mode Protected Mode Virtual Real Mode 16 bit instructions/use only 1MB of memory Protected Mode 32 bit instructions/applications run in protected memory spaces Virtual Real Mode Used in Windows for backwards compatibility

Processor Features SMM (System Management Mode) Superscalar Execution Power Mgmt. Standard used in portables Superscalar Execution Execute multiple instructions simultaneously

Processor Features MMX (Multi Media eXtensions) Dynamic Execution Improves video, imaging, and I/O processing Dynamic Execution Anticipates a programs needs before hand DIB Architecture (Dual Independent Bus) Separate busses for memory access

Processor Features L1 cache L2 cache Built into CPU As fast as CPU, 90% success rate L2 cache Previously, always located on motherboard Faster than RAM, slower than CPU 90% success rate Trend: locating on CPU Smaller faster cache better than slower bigger cache

Most Common Processor Sockets Used by Pentium and Pentium MMX Still being used by AMD and Cyrix under the name Super 7 Slot 1 - Used by Pentium II. Looks like a cartridge Cache mounted in slot for faster access Not used by any other manufacturer