1. Introduction to Computers

2. Factors in processor Performance
Clock speed
Most vital, dictates instructions executed per second
Word Size
Dictates number of bits per instruction & usable RAM
Front side bus (FSB) speed
Speed of data pathway between memory & processor
Cache size
Ability to hold latest instructions/data in fast memory
Number of processor cores
Allows multiple tasks to execute simultaneously

3. Clock speed
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

4. Word size
Word size determines how many bits the processor can accept with each instruction
PC’s went from 32 to 64 bit processors recently
Allows addressing of RAM in excess of 4GB
But many older 32 bit processors remain in use
Larger word size means faster execution
Minor performance increase, not twice 32 bit speed
Lots of 32 bit application software still in use
But Windows is a fully 64 bit operating system

5. Front side bus
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

6. Cache size
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

7. Multicore Processors 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
Much application software does not at this time
Multi-core processor gains mostly in multi-tasking

8. The instruction set 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

9. Processor families The X86 family The ARM family
Includes processors from two competing firms, Intel and Advanced Micro Devices (AMD)
Mac & Windows PC’s use this family of processors
Originally based on Intel processor architecture
The ARM family
Reduced instruction set approach uses less power
Designed from the start to be highly power efficient
Intended for and used with mobile Android devices
PowerPC family not used in personal computers

10. The Intel & AMD processor Lines
High end personal computer processors
Intel – Core i series… Core i3, Core i5, Core i7, and Core i9
AMD – Ryzen and FX series
Midrange priced processors
Intel – Pentium
AMD – Athlon and A series
Budget processors
Intel – Celeron
AMD – Sempron
High end server/high performance computing
Intel – Xeon or Itanium
AMD - Opteron

11. ARM Processors for mobile devices
Some widely used processors found in Android smart phones and tablets are:
Qualcomm – Snapdragon processor
Intel – Atom processor
Samsung – Exynos processor
Nvidia – Tegra processor
Apple makes its own proprietary processors solely for use in the iPhone & iPad
But uses the X86 family for its Mac computers

12. High-end versus budget
Budget processor lines are great for most users
Most users have fairly basic needs
Web browsing, , music, etc.
The more sophisticated your needs, the more the need for the high-end processor
Gaming in particular needs a high end processor
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. Random Access memory 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. Current RAM requirements
Most new computers have 4 to 12 GB of RAM
Very low end computers may have 2GB
Computers designed for gaming often have 16GB
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. Virtual memory
Virtual memory is main storage 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
Main storage 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. Different types of RAM Computers use SDRAM almost exclusively
Different types of SDRAM include DDR3 and DDR4
RAM has different access speeds
Sometimes measured in nanoseconds
A nanosecond (1 ns) is a billionth of a second
If nanoseconds used, a lower number is faster
More commonly measured in GHz
If GHz used, a higher number is faster

17. Purchasing memory 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. A common RAM Upgrade issue
Say you have 4GB of RAM with an 8GB capacity
So to upgrade, you need another 4GB, right?
Not necessarily
PC with 8GB capacity may have 2 DIMM slots
If you already have 4GB of RAM, often times it’s installed as two 2 GB DIMMs, taking up both slots
So you must buy two 4GB DIMMs to maximize RAM
You end up throwing out 4GB of memory because it came as two 2GB DIMMs instead of one 4GB DIMM

19. Read only memory 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. Storing configuration settings
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
EEPROM an early version of today’s flash memory

21. What do these computers cost?
Computer # inch display, non-touch
Intel Celeron processor, 2.48 GHz, 2MB Cache
4GB DDR3 at 1.6 GHz, Up to 8GB
500GB Hard Drive, 5400 rpm
Computer #2 – 15.6 inch 2-in1 touch display
Intel Core i7, 3.5 GHz, 4MB Cache
12GB DDR4 at 2.4 GHz, Up to 16GB
512GB Solid State Drive
$299
$979