1. Central Processing Unit (CPU)
Computer Service and Repair
Chapter 4
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2. Instructions and Data The CPU is the computer’s brain
In 1978 had 27,000 transistors now they have over 2.5 billion
CPU follows commands called instructions
Instruction set is the set of basic commands all CPUs follow
Add / subtract
Compare
Add one to / subtract one from
Get the next one, two, or, four bytes from
Put the next one, two, or four byte at
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3. Instructions and Data (cont’d)
The Instruction Set is written in assembly language – the lowest language level used to program a computer (one step up from machine language)
A compiler is a program that translates higher level programs into machine language
A register is a small pocket of memory in a CPU used to temporarily store data that is being processed
add number stored in register A to number stored in register B place result in register C
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4. CPU Operation CPU is in constant operation Refreshing memory
Checking for communication from other devices
Monitoring system power
Performing other programmed duties
Checking IRQ status
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5. CPU Operation (Cont’d)
CPU Parts
Bus Unit: network of circuitry that connects all off the other major components together
Instruction Cache: small temporary memory to store incoming data and instructions
Decode unit: decodes instructions
Control Unit: controls overall operation of CPU
Arithmetic logic unit (ALU) performs math functions
Register unit: composed of many separate storage units (register hold only one number or letter each)
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6. CPU Operation (Cont’d)
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7. CPU Operation (Cont’d)
Not all business conducted on a PC requires the use of a powerful CPU
i.e. word processor
Powerful CPU needs for graphic intense programs, weather, or CAD programs
i.e. 3D animation that requires redrawing every line of image and calculations based on X,Y, & Z coordinates in fractions of a second
To save CPU time data not requiring manipulation are now transferred directly to memory
System clock send repetitive signal to all parts of system to keep data transmissions in step
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8. CPU Operation (Cont’d)
CPU speed is measured in hertz Hz (cycles per second)
Number of digital pulses per second
Hertz is often referred to as frequency
Speed became important as user interface switched from text to GUI
Each new generation of CPU operated on shorter clock cycles (frequency)
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9. Enhancing CPU Operation
In addition to speed CPU have Improved:
Local Bus: links devices directly to CPU
RAM
Video card slots
Referred to as system bus or front side bus
Shortened bus reduces inductive reactance
Cache
L1 cache is designed to run at same speed as CPU
L1 allows CPU to quickly process data
Two L1 Cache for each processor (one for instruction and one for data)
L1 memory is most costly to produce
L1 is small on inexpensive processors
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10. Enhancing CPU Operation (cont’d)
L2 Cache: used to increase data from the processor to other parts of the motherboard
Originally separate from CPU mounted close on motherboard
Moved in CPU with Pentium III
L3 Cache:
Originally added to mother board to speed when L2 moved to CPU
Now on CPU (shared between multi core CPUs)
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11. Enhancing CPU Operation (cont’d)
Floating Point Unit (FPU): a set of circuits in the CPU that replace the math coprocessor that was originally on the mother board
Multiple Branch Prediction: guesses what data the CPU will need next instead of waiting for instructions to be issued (90% accurate)
Superscalar execution: processing more than one instruction at a time
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12. Enhancing CPU Operation (cont’d)
Dynamic Execution: CPU looks ahead if an instruction can be carried out faster than the instruction preceding it, it is moved ahead an executed.
Integrated Memory Controller: (IMC) Controls data flow in front side bus to / from RAM
Integrated Graphics Processing: (GPU) enhances the ability of computer to produce video and 3-D images
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13. Enhancing CPU Operation (cont’d)
Dual Independent Bus (DIB): Two separate bus systems incorporated into the CPU
One for Main Memory
One for L2
Both buses are use simultaneously
Simultaneous Threading
Thread is part of a software program that can be executed independently
Multi-core processors use two threads per core (quad core runs 8X as fast as single core)
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14. Enhancing CPU Operation (cont’d)
Overclocking: running a CPU at frequencies higher than rated.
Raises heat
Can / will damage CPU
CPU can accomplish more tasks in shorter time
Frequencies can be controlled by BIOS
Turbo Boost Technology / Turbo CORE
Overclock CPU
Monitor temperature and energy use
Halts overclocking if temp gets to high
Intel provides free software (Intel Extreme Tuning Utility)
Voids warranty
Intel does not recommend
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15. Process Description Features
Reduced Instruction Set Computer (RISC): a CPU Produced with fewer transistors and instruction
Inexpensive but fast
Software has carry modifications that allow for fewer CPU computations
Used in IPad, Iphone, Android, auto engine controls, TVs, airplanes, robots, and servers
Complex instruction set computer (CISC): A CPU that processes complex mathematical formulas at increased clock speed
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16. Process Description Features (cont’d)
MMX Processor: based on standard processor with the addition of 57 commands.
Enhances ability of CPU to support graphic technology
Replaces functions of video and sound cards
MMX could mean Multi-Media eXtensions, Mtrix Math eXtensions, or as Intel claims nothing at all
32 bit vs 64 Bit (64 faster.)must have following:
BIOS must support 64 bit technology
64 bit O/S
64 bit drivers
Software written for 64 bit systems
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17. Process Description Features (cont’d)
Virtualization: a single physical CPU appear as multiple processors to the system software and the user.
Allows multiple operating systems, users, and application software simultaneously
Normally applied to network servers
System Management Mode: (SMM) Designed for laptops to save energy
Sleep
Auto shut down
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18. Process Description Features (cont’d)
Cool ‘n’ Quiet (Process throttling): adjust process speed and power consumption based on temperature and software usage. Fan speed may also be slowed
Enhanced Intel SpeedStep Technology: When laptop is plugged in Runs on 2.6 GHz applied 1.3 volts overall power consumed is 30 watts. When on battery runs at 1.3 GHz and 1.2 volts overall power consumed 20.8 watts
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19. Process Description Features (cont’d)
CPU operating voltage has dropped from 5 Volts to less than 1 volt
Processor Size (physical) has not changed significantly but the electronics have become more compact
Moore’s Law: (1965) Gordon Moore cofounder of Intel predicted that computer calculating power would double every year. He has been pretty close (now takes about 18 months)
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20. Processor Manufacturers
Three Biggest:
Intel is the dominate manufacture of CPUs since 1970’s
AMD Intel’s biggest competitor.
VIA Technologies is not as large as Intel or AMD make processors and motherboards with intel, AMD, and their own processors
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21. Processor Evolution Intel Pentium (1993): front side bus
Intel Pentium Xeon (Xeon 1998)
network servers
Hyper threading
Not designed for entertainment
Multiprocessors on each board ( blade servers)
Used in web servers, cloud storage, and networks
Intel Celeron (1999) general purpose computers
Limited L1 and L2 counters high speed processor results in less overall performance
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22. Processor Evolution (cont’d)
AMD Athlon 64 (2002) uses 32 and 64 bit processing
AMD Opteron (2003)
for Network Servers
64 bit
Can process 256 TB
Usually runs between 800 MHz – 2.6 GHz
19 GB throughput
AMD Sempron (2004)
Low cost computers
Two types (front bridge or HyperTranport)
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23. Processor Evolution (cont’d)
AMD Athlon 64 X2 (2005) 64-bit dual core
AMD Athlon 64 FX (2006) introduced new socket
Intel Core Solo (2006) designed for laptops
Intel Dual Core (2006) Intel’s first dual core
Intel Dual Core 2 Duo (2006)Dual core, front bus, variable L2
Intel Core 2 Extreme (2007) gaming, 8MB L2
Intel Core 2 Extreme Quad (2007) four processors
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24. Processor Evolution (cont’d)
Intel Core i3 (2011) minimal computing power for devices that use the cloud
Intel Core i5 (2011) intermediate processor does not have Hyper-Threading good for average computer systems with limited multi-media editing capabilities
Intel Core i7 (2011)High Performance CPU
Turbo boost technology
Hyper-Threading
Larges L3 Cache
Two types i7 & I7 Extreme (better graphics)
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25. Processor Evolution (cont’d)
Intel Atom: Specialized for low power consumption and low heat
32 and 64 bit
Single and dual core
Netbooks, tablets, smart phones
AMD FX: Best AMD to Date
4,6,or 8 core
3-D graphics
Designed for over clocking
First CPU with 8 cores
AMD A-series
A4, A6, A8, and A10 similar to Intel i3, i5, i7
AMD and Intel are too similar to say one is better than the other must test specific software used to determine best for your use
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26. Processor Affinity
Processor Affinity is the ability to select the number of cores to apply to a software application
System and Software must be designed to operate in the multi core environment
Software / system may lockup if mismatched
Deselect any number of processors from CPU 0 to CPU 7 to run the software application in the Task Manager by selecting Processor Affinity
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27. Processor Sockets
Processor Sockets vary according into the number of electrical connections.
AMD and Intel are not interchangable
AMD – Land Grid Array (LGA) Lands are small Flat connectors
Intel – Pin Grid Array (PGA) connectors are pins
Originally techs pushed CPUs into Socket
Lands and pins could be damages easily
Zero Insertion Force Socket (ZIF) has one or two levers the clamp onto pins or lands
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28. Processor Performance
CPU is not the only thing that affect system speed
Download and Use a CPU analyzer
CPU-Z is free
Download from Cupid
Will identify CPU
L1 and L2 size
Socket type
Core and bus Speed
more
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29. Questions to ask before Upgrading CPU
What are you trying to achieve by upgrading CPU
Is the upgrade CPU compatible
Will Chip set and BIOS support the upgrade
Does the motherboard bus speed or chipset rather than the CPU limit the increase in speed
Does the chipset support desired features of the new CPU such as 3-D tech
Note:
Cables / Modems affect download speed
If main function is typing new CPU little effect
If gaming new CPU May help is motherboard and chipset support it
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30. Installing a Processor
Remove cooling Device
Release locking lever(s)
Lift out CPU
Align pins (lands) to socket
Gently drop CPU into socket
Close locking levers
Reinstall cooling device
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31. Installing a Processor
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32. Cooling the Processor
Electronic integrated circuits start to break down at 160 degrees F
Three Type of Cooling
Simple heat sink and fan (most common)
Heat sink paste
Heat pipe cooling system (high performance)
Hollow tubes with liquid that vaporizes and condenses at the heat sink and returns to CPU by capillary action
Liquid Cooling System (very high performance)
Liquid is pumped rom CPU to a small radiator and back to CPU (Most Expensive)
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33. Heat Sink and Fan
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34. Heat Pipe Cooling System
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35. Liquid Cooling System
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36. End of Chapter 4
Questions?
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