- This system of pathways used for communication and the protocol and methods used for transmission are collectively called the bus.
- The parts of the bus that we are most familiar with are the lines of the bus that are used for data; these lines are called the data bus.
- PCI and PCIe, PCIe 2, PCI- X
Wait state (Buses)
A clock tick in which nothing happens, used to ensure that the microprocessor isn’t getting ahead of slower components. A 0-wait state is preferable to a 1-wait state. Too many wait state scan slow down a system.
Electrical Power (Buses)
A bus can also carry electrical power (to power components on the motherboard),
Control Signals (buses)
control signals (to coordinate activity)
memory addresses (for one program to tell another program where to find data or instructions).
- All data and instructions inside a computer exist in binary, which means there are only two states: on and off. Binary data is put on a line of a bus by placing voltage on that line.
- The width of a data bus is called the data path size.
- Some buses have data paths that are 8, 16, 32, 64, 128, or more bits wide.
- speed for buses PCI express Version 2, 1.1, 1 and X.
- Throughput is sometimes called bandwidth
- is one method of resetting a computer system that is already powered on, commonly used to recover from errors that cannot be recovered, or when a computer locks.
- A warm boot can be accomplished by pressing the CTRL - ALT - DEL keys simultaneously, or by selecting the restart command from an operating system menu.
- Warm boots run faster than turning a computer off and on again.
- power-on self test
- A self-diagnostic program used to perform a simple test of the CPU, RAM,and various I/O devices. The POST is performed by startup BIOS when the computer is first turned on, and is stored in ROM-BIOS.
- Startup BIOS: Part of system BIOS that is responsible for controlling the computer when it is first turned on. Startup BIOS gives control over to the OS once it is loaded.
A boot sector or boot block is a region of a hard disk, floppy disk, optical disc, or other data storage device that contains machine code to be loaded into random-access memory (RAM) by a computer system's built-in firmware.
MBR (Master Boot Record)
is a special type of boot sector at the very beginning of partitioned computer mass storage devices like fixed disks or removable drives intended for use with IBM PC-compatible systems and beyond.
The Windows program needed to start Windows is missing or corrupted. This program is called the OS boot manager program.
NTLDR (new technology loader)
- is the boot loader for all releases of Windows NT operating system up to and including Windows XP and Windows Server 2003.
- Missing NTLDR: The Windows program needed to start Windows is missing or corrupted. This program is called the OS boot manager program.
To keep the board from touching the case, screw holes are elevated, or you’ll see spacers, also called standoffs, which are round plastic or metal pegs that separate the board from the case.
Bios: Power Menu
- setup for configuration motherboards
- Managing the power
Bios: Boot Sequence
Order in which the system tries to boot from certain devices (called the boot sequence or boot priority).
Bios: Password Protection
Some motherboards and hard drives allow you to set a password that must be entered before someone can access the hard drive. This password is kept on the drive and works even if the drive is moved to another computer.
Characteristics of processors: system busses
The bus between the CPU and memory on the motherboard. The bus frequency in documentation is called the system speed, such as 400 MHz. Also called the memory bus, front-side bus, local bus, or host bus.
Characteristics of processors: Processor Core
Processor core frequency is measured in gigahertz, suchas 3.3 GHz.
Characteristics of processors: Multiprocessing
- Two processing units installed within a single processor and first used by the Pentium processor.
- The ability of a system to do more than one thing at a time is accomplished by several means:
- Two processing units (called arithmetic logic units or ALUs) installed within a single processor
Characteristics of processors: Cache
- Memory cache, which is the amount of memory included within the processor package.
- Today’s processors all have some memory on the processor chip (called a die).
- Memory on the processor die is called Level 1 cache (L1 cache).
- Memory in the processor package, but not on the processor die, is called Level 2 cache (L2 cache).
- Some processors use a third cache farther from the processor core, but still in the processor package, which is called Level 3 cache (L3 cache).
- Processor can support DRAM, DDR, DDR2, DDR3.
Characteristics of processors: Hyper-Threading
- AKA multithreading
- Each processor or core processes two threads at the same time.
- When Windows hands off a task to the CPU it is called a thread and might involve several instructions.
- To handle two threads, the processor requires extra registers, or holding areas, within the processor housing that it uses to switch between threads.
- in effect, you have two logical processors for each physical processor or core.
- Intel calls this technology Hyper-Threading and AMD calls it HyperTransport.
- The feature must be enabled in BIOS setup.
Front side bus
- was a computer communication interface (bus) often used in Intel-chip-based computers during the 1990s and 2000s
- replaced by multithreading.
- The bus between the CPU and memory on the motherboard.
- A bus that operates only within the internal circuitry of the CPU, communicating among the internal caches of memory that are part of the CPU chips design.
- The CPU can put data or instructions on its internal bus at a much higher rate than does the motherboard.
- is a computer bus used to connect the CPU to CPU cache memory, usually L2
- The speed at which the processor operates internally
- For example, if the processor operates at 3.2 GHz internally but the Front Side Bus is operating at 800 MHz, the processor operates at four times the FSB speed.
The factor by which the bus speed or frequency is multiplied to get the CPU clock speed.
- Use power management settings to conserve power and to increase the time before a battery pack needs recharging. Power is managed by putting the computer into varying degrees of suspend or sleep modes.
- sleep mode and hibernation.
Advanced Configuration and Power Interface (ACPI)
- power standards, BIOS might refer to five S states, S1 through S5, used to indicate different levels of power-saving functions.
- In S1 state, the hard drive and monitor are turned off and everything else runs normally.
- In S2 state, the processor is also turned off.
- In S3 state, everything is shut down except RAM and enough of the system to respond to a wake-up.
- S3 state is sleep mode.
- S4 state is hibernation.
- S5 state is the power off state after a normal shutdown.