CompOS Chapter 3

What happens while the CPU is executing program code?

Instructions or data that are likely to be used are fetched form main memory and placed in cache memory.

Who is the most popular CPU manufacturer today?

Intel.

What is the Data Bus?

It allows computer components, such as CPU, to share information.

What is Hyper-Threading?

It allows two threads to run on each CPU core simultaneously.

What is the Control Bus?

It carries status signals between the CPU and other devices.

What is CPU scheduling?

It determines which process to start given the multiple processes waiting to run.

What is a System bus?

It is a series of lanes used to communicate between the CPU and other major parts of the computer.

What is Microcode?

It is a small program inside the chip that interprets and executes each instruction.

What is multithreading?

It is the ability to run two or more processes (known as threads) at the same time

What is the Cache Controller?

It predicts what data will be needed and makes the data available in cache before it is needed.

What is the instruction set?

It's the list of commands the CPU can understand and carry out.

Who developed PowerPC chips?

Joint group of Apple Computer, IBM, and Motorola (AIM)

Differences between CISC and RISC include:

1. Complex vs. Simple instructions 2. Clock Cycles 3. Pipelining 4. Hardware vs. Microcode 5. Compiler 6. Number and usage of registers

What is microarchitecture?

1. The description of a CPU's internal circuitry. 2. Defining characteristics (tech used to create the chip) 3. Supported instruction set. 4. Bit size

How many processes per second for a low end CPU?

20 million.

What type of Address Bus do modern processors use?

64-bit address bus. It allows them to address 16 TB of memory.

SPARC: Scalable Processor Architecture

A RISC processor.

What is the CPU?

A chip that performs the actual computational and logic work.

What are Interrupt Requests (IRQ)?

A request to the processor to "interrupt" whatever it is doing to take care of a process, which in turn might be interrupted by another process.

What is the Register?

A temporary holding location where data must be placed before the CPU can use it.

What are the two general CPU designs used today?

Complex Instruction Set Computing (CISC) and Reduced Instruction Set Computing (RISC)

What is the Address Bus?

An internal communications pathway that specifies the source and target addresses for memory reads and writes.

Which CPU has fewer registers? CISC or RISC?

CISC CPUs have fewer registers than RISC CPUs.

More components are needed to make a CPU, thus they use more energy. So CPUs need?

CPUs need fans to keep cool due to the extra energy being converted into heat.

What are the three types of buses?

Control, Address, and Data bus.

Intel processors were initially?

Developed with one core.

Level 1 Cache (L1)

Fastest and usually runs at the same speed as the CPU

How many levels of Cache are there?

Four levels. Level 1 - Level 4

Where was the Alpha Chip found?

High-end HP Compaq servers

What do the number of bits in the data bus indicate?

How many bits of data can be transferred from memory to the CPU in one clock tick.

What were the early Intel processors?

Identified by model numbers: 8088, 8086, 80286, 386, 486. Sometimes preceded by an i (i386)

PowerPC Chips

Line of chips that used different instructions sets than the Motorola 68xxx line

What is Advanced Micro Devices (AMD)?

Manufactures CPU chips that compete with Intel.

What type of computer have multiple physical CPU chips?

Multiprocessor Computers

Level 3 Cache (L3)

Not part of the CPU chip, but part of the motherboard.

The Alpha Chip

Originally designed by Digital Equipment Corporation (DEC), eventually purchased by HP.

What is the Control Unit?

Part of the CPU that provides timing and coordination between other parts of the CPU.

Internal Clock Speed

Provides a rigid schedule to make sure all the chips known what to expect at what time.

What is a Core?

Section of the processor that actually does the reading and execution of instructions.

How many processes per second for a high end CPU?

Several billion.

Level 2 Cache (L2)

Slower, but much larger

CPU Speed

Speed of a CPU defines how fast it can perform operations.

Who designed SPARC Chip?

Sun Microsystems

What is the Arithmetic Logic Unit (ALU)?

The ALU performs the primary task of executing instructions.

Which chip was the first to reach a speed of 1 GHz?

The Alpha Chip

What is the current version of the SPARC chip?

The SPARC M7. A 64-bit chip with a 64-bit address and data bus.

What is Pipelining?

The ability of the CPU to perform more than one task on a single clock cycle.

What is the difference between CISC and RISC?

The number of instructions that the chip can process.

AMD named are based on?

The series, (Athlon and FX), and the core architecture (Zambezi and Vishera)

What is a thread?

The smallest piece of computer code that can be independently scheduled for execution.

External Clock Speed

The speed at which the processor communicates with the memory and other devices in the computer; usually one-eighth to one-half the internal clock speed

What is built around the CPU?

The system architecture of the computer, including the number and type of CPUs in the hardware and the communication routes between CPUs and other hardware components.

The Motorola 68xxx Chips

Typically found in Macintosh computers and older UNIX

What speed does the Address Bus run?

Typically runs at the external clock speed of the CPU

Level 4 Cache (L4)

Will usually be found on motherboard (if it exists)

Do most modern CPUs have cache memory built into the chip?

Yes.