CPU CPU-Central Processing Unit, The CPU is the brain of the computer. Sometimes referred to simply as the processor or central processor, the CPU is where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system. The two biggest manufacturers of PC CPU chips are those made by Intel and AMD other CPU makers include Motorola, Via, and Cyrix Central Processing Unit (The Brain of the Computer) Two typical components of a CPU are: The arithmetic logic unit (ALU), which performs arithmetic and logical operations The control unit, which extracts instructions from memory and decodes and executes them, is calling on the ALU when necessary. CPU Terminology Clock speed: Given in megahertz (MHz) or higher (GHz), the clock speed determines how many instructions per second the processor can execute. Also called clock rate, the speed at which a microprocessor executes instructions. Every computer contains an internal clock that regulates the rate at which instructions are executed and synchronizes all the various computer components. The CPU requires a fixed number of clock ticks (or clock cycles) to execute each instruction. The faster the clock, the more instructions the CPU can execute per second. Clock speeds are expressed in megahertz (MHz), 1 MHz being equal to 1 million cycles per second. 1 MHz = 1 million clock cycle 1 GHz = 1 billion clock cycle Bus Speed The speeds in which a processor can send data in a pathway. There measured in the following speeds listed below: 33MHz, 66MHz, 100MHz, 133MHz, 166MHz, 200MHz, 233MHz, 266MHz, 333MHz, 400MHz, 800MHz, 1600MHz, 3200MHz and 6400MHz Bus Width 32 vs. 64 bit Address Bus: Refers to the wires that carry specific addresses to and from the processor. Cache: Frequently stored memory, most older CPU's have an L1 internal cache built in with an L2 external cache support chips. Newer CPU's like the pentium IV have and L1 and L2 cache built in with a L3 cache Cache is a very fast memory that is used to hold data and instructions VRM (Voltage Regulator Mode) Is the circuitry that sends standard level voltage to the CPU RISC vs. CISC Reduce Instruction Set Computing vs. Complex Instruction Set Computing Math Co Processor Ability of a CPU to perform math functions and advance calculations Cooling Mechanism Devices use to cool a CPU (FAN, Heat Sink and Liquid Cooling) also thermal paste Overclocking Making a CPU run faster than it should Front Side vs. Backside Bus How the CPU communicates with the memory and the cache Hyperthreading Is a technology developed by Intel that acts as two processors Multicore or Dual Core, Triple Core or Quad Core Has the capability to act as separate processor in the same CPU Instruction set: The set of instructions that the microprocessor can execute. Bandwidth: The number of bits processed in a single instruction. Pipelining - Allows a new instruction to start processing while a current instruction is still being processed. Branch Prediction - A technique that attempts to infer the proper address of the next instruction while knowing only the current one. Superscalar execution - Adding one more execution engine in a CPU Dynamic execution - Allows the CPU to evaluate the programs's flow and choose the best order in which to process the instructions Registers: Temporary storage areas that hold data before and after processing by the ALU. It similar to a work table use by the CPU Computer Packages, Slots and Sockets SEC- Single Edge Cartridge a new CPU package that is slightly bigger with a built in fan that goes into a SLOT 1 or SLOT A socket. AMD Athlon SEC SLOT 1 - The form factor for Intel's Pentium II processors The Slot 1 package replaces the Socket 7 and Socket 8 form factors used by previous Pentium processors. Slot 1 is a 242-contact daughter card slot that accepts a microprocessor packaged as a Single Edge Contact (SEC) cartridge. A motherboard can have one or two Slot 1s. Some Pentium III and Celeron also use SLOT 1. SLOT A - Similar to Intel's Slot 1 but used for AMD Athlons SLOT 2 Slot 2 is a 330-contact use by Intel Pentium II, III XEON found mostly on server computers PGA-Short for pin grid array, a type of chip package in which the connecting pins is located on the bottom in concentric squares. PGA chips are particularly good for chips that have many pins, such as modern microprocessors. They go into different types of CPU sockets. Different types of PGA SPGA: Staggered Pin Grid Array BCPGA: Ball Chip Pin Grid Array FCPGA: Flip Chip Pin Grid Array CPGA: Ceramic Pin Grid Array BPGA-Ball Pin Grid Array ZIF - Zero insertion force, a chip socket that allows you to insert and remove a chip without special tools. Socket - A female connector where a CPU connects Note * PGA and LGA fits into a socket and SEC packages fits into a slot Other CPU packages include the following: PAC - Pin Array Cartridge (Use in Itanium CPU's) LGA - Land Grid Array (Newer technology replacing PGA) Use grid instead of pins Newer CPU CHART Socket or CPU Package Slot Socket Intel Pentium 4/Core and Celeron PGA 423/478 Intel Pentium 4, Extreme, Pentium D, Socket T Celeron D, Dual Core, Core2, LGA (Socket 775) Duo/Extreme/Quad/Xeon Socket H Intel Pentium, Core, i Series, Xeon LGA (Socket 1156) Socket B Intel Core, i Series, Xeon LGA (Socket 1366) Socket B (Socket 1366) LGA Intel iCore 7 Series Socket H uPGA (Socket 1156) Socket 989 AMD K7 Athlon, Athlon XP, MP, Socket A PGA Duron, Semprom, Geode, NX (Socket 462) AMD K8, AMD Athlon 64, Semprom PGA Socket 754 Socket AMD Athlon 64/64X2, Opteron, PGA 939/940 or Phenom, X2/X3, X4, X4 II Socket AM2 Socket AMD Athlon II, Phenom II, Semprom PGA AM2+, Socket AM3 Socket F AMD Athlon 64FX, Opteron PGA (Socket 1207) Socket or CPU Servers and Workstations Package Slot Intel Pentium II and Pentium III Xeon SEC Slot 2 (330) Intel Itanium PAC Socket 418 Intel Itanium II PAC Socket 611 Socket Intel Xeon LGA 603/604 Socket J Intel Core 2, Extreme, Xeon LGA (Socket 771) Socket F (Socket AMD Athlon 64FX, Opteron PGA 1207) Socket 940 Older CPU CHART Intel CPU Chart AMD CPU Chart CPU Troubleshooting Problems with heat (cooling mechanism FAN, Heat Sink and Liquid Cooling) 5 Minute shut down (CPU is overheating) Listen for fan for breakdown and weird unusual noises Computer won't start Computer is acting erratic Keep air case tight CPU Compatibility (look at chart) Overclocking (make sure you have the proper cooling mechanism to support this or you will damage your CPU) When installing CPU be careful don't bend or break pins Match PGA to Socket (ZIF) and SEC to Slot ZIF (Zero Insertion Force) Match Pin 1 to the socket or look for notches when installing CPU Avoid ESD by grounding one's self Make sure CPU use the proper voltages CPU Installation CPU package must match pin 1 with CPU Socket Put thermal compound on CPU and install proper cooling mechanism (Fan, Heat Sink or Liquid) CPU SEC slide in CPU slot and install proper cooling mechanism (Fan, Heat Sink or Liquid).