2. Unit 3 Processors and Memory Section B

3. Chapter 1, Slide 2Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 2 Clock speed Dictates instructions executed per second Word Size Dictates how many bits accepted per instruction Front-side bus (FSB) speed The data pathway between memory and processor Cache size Recent instructions/data retained in fast memory Number of processor cores Allows multiple tasks to execute simultaneously

4. Chapter 1, Slide 3Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 3 A microprocessor is a single integrated circuit or chip designed to process instructions Clock speed determines number of instructions executed each second by processor One instruction executes at each “tick” of the clock Clock speeds expressed in gigahertz (GHz) 1 GHz is a billion ticks in a second Higher clock speeds mean faster execution

5. Chapter 1, Slide 4Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 4 Word size determines how many bits the processor can accept with each instruction Transition to 64 bit processors nearly complete64 bit processors Most all new computers use a 64 bit processor Many continue to use existing computers with 32 bit processors Larger word size means faster execution But this is a minor increase in performance A 64 bit processor is not twice as fast as 32 bit

6. Chapter 1, Slide 5Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 5 Front-side bus is the pathway that moves data and instructions from memory to processor Like clock speed, FSB speeds are typically expressed in gigahertz (GHz) A smaller FSB speed means data takes longer to get from memory to processor A slow FSB can drag down processor performance

7. Chapter 1, Slide 6Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 6 Cache refers to very fast memory integrated into the processor chip The larger the cache size the better Data and instructions transferred from RAM to the processor are stored in cache When the processor needs data or instructions it always checks for it in cache first If already in cache, there’s no need to retrieve the data from RAM, increasing performance

8. Chapter 1, Slide 7Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 7 Multi-core processors are a recent development Designers hit several physical limitations in trying to improve processor performance Designing multiple processors on one chip is a way to circumvent these limitations Software must be redesigned for multi-core Operating systems take advantage of multi-core Most application software does not at this time Multi-core processor gains mostly in multi-tasking

9. Chapter 1, Slide 8Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 8 Every processor has an instruction set The list of instructions that processor can perform This is built in or hardwired into the chip Processors are grouped into families Processors in a family are compatible with other processors in that family Members of a family use the same instruction set The processor executes instructions found in a computer program

10. Chapter 1, Slide 9Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 9 Intel family Includes processors produced by two companies, Intel and Advanced Micro Devices (AMD) Windows PC’s use this family of processors Based on X86 processor architecture The PowerPC family Designed by an Apple, IBM, and Motorola alliance Used by Macintosh until recent switch to Intel X86 Still heavily used in non-Windows IBM computers

11. Chapter 1, Slide 10Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 10 Intel and AMD compete in processor market High end personal computer processors Intel – Core i series… Core i3, Core i5, or Core i7 AMD – Phenom or Athlon Budget priced personal computer processors Intel – Celeron AMD – Sempron High end server/high performance computing Intel – Xeon or Itanium AMD - Opteron

12. Chapter 1, Slide 11Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 11 Budget processor lines are great for most users Most users have fairly basic needs Web browsing, email, music, etc. The more sophisticated your needs, the more the need for the high-end processor Especially gaming and other high-end video needs Celeron is based on high-end processors but: Runs at a lower clock speed Has less cache memory Has a slower front-side bus (FSB)

13. Chapter 1, Slide 12Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 12 Random access memory (RAM) is main storage Holds anything needed for current processing This includes both data and instructions As you enter text into a Word document, the characters you type are stored in RAM Operating system instructions held in RAM as well RAM is volatile, requires power to hold data Each RAM address consists of 8 sets of on/off switches called capacitors

14. Chapter 1, Slide 13Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 13 Most computers now have 1 to 4 GB of RAM Amount of RAM needed depends on software used and number of programs run concurrently Easy to purchase and install additional RAM Can’t run out of RAM If RAM fills, computer will use virtual memory

15. Chapter 1, Slide 14Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 14 Virtual memory is hard disk space formatted to “look” like RAM If RAM fills, the least frequently used task is swapped out to virtual memory There’s a noticeable time delay when this happens Hard disk is incredibly slow compared to RAM Task automatically swapped back in if reactivated Another noticeable time delay when swapping in Minimize use of virtual memory

16. Chapter 1, Slide 15Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 15 Computers use SDRAM almost exclusively Different types of SDRAM include DDR2 and DDR3 RAM has different access speeds Often measured in nanoseconds A nanosecond (1 ns) is a billionth of a second If nanoseconds used, a lower number is faster Sometimes measured in MHz or GHz If MHz or GHz used, a higher number is faster

17. Chapter 1, Slide 16Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 16 Be sure to buy RAM compatible with your PC It’s often best to check with the manufacturer Manufactured as individual chips called DIPs DIPs soldered on a circuit board called a DIMM Stands for Dual In-line Memory Module Memory is sold and installed as a DIMM Easy to install, plugs into a slot on the motherboard

18. Chapter 1, Slide 17Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 17 Say you have 2GB of RAM with a 4GB capacity So to upgrade, you need another 2GB, right? Not necessarily PC with a 4GB capacity may have 2 DIMM slots If you already have 2GB of RAM, often times it’s installed as two 1 GB DIMMs, taking up both slots So you must buy two 2GB DIMMs to maximize RAM You end up throwing out 2GB of memory because it came as two 1GB DIMMs instead of one 2GB DIMM

19. Chapter 1, Slide 18Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 18 ROM is permanent and non-volatile Holds instructions required in boot up process RAM empty when computer is started, so ROM is the source of initial boot up instructions Provides instructions for computer to find and begin loading operating system from hard disk Only way to change the instructions on a ROM chip is to replace the chip

20. Chapter 1, Slide 19Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 19 Due to the volatile nature of RAM, cannot store configuration settings there These settings must be maintained with power off ROM not an option, must be able to change configuration settings change Configuration settings stored in an EEPROM Electrically erasable programmable read-only memory EEPROMs replace CMOS, no longer need a battery

21. Chapter 1, Slide 20Starting Out with Visual Basic 3 rd EditionIntroduction to ComputersUnit 3B – Processors and MemorySlide 20 Computer Ad #1 AMD Athlon II, 2.9GHz, 2MB Cache 4GB DDR3 SDRAM at 1,333 MHz – 4 DIMMs Computer Ad #2 Intel Celeron, 2.2 GHz, 512KB Cache 2GB DDR3 SDRAM at 1,333 MHz – 2 DIMMs