Install and Configure CPUs Flashcards
CPU
The central processing unit (CPU) is the principal system controller and has the greatest overall impact on system performance.
CPU Architecture
When a software program runs (whether it be system firmware, an operating system, antivirus utility, or word-processing application), it is assembled into instructions utilizing the fundamental instruction set of the CPU platform and loaded into system memory.
- The control unit fetches the next instruction in sequence from system memory to the pipeline.
- The control unit decodes each instruction in turn and either executes it itself or passes it to the arithmetic logic unit (ALU) or floating-point unit (FPU) for execution.
- The result of the executed instruction is written back to a register, to cache, or to system memory.
Register
A register is a temporary storage area available to the different units within the CPU working at the same clock speed as the CPU.
Cache
Cache is a small block of memory that works at the speed of the CPU or close to it, depending on the cache level. Cache enhances performance by storing instructions and data that the CPU is using regularly.
x86 CPU Architecture
The x86 CPU architecture is a family of instruction sets developed by intel. The original 8086 processor was 16-bit instruction set processor designed by Intel in 1978.
x64 CPU Architecture
x86 is a 32-bit instruction set. 32-bit means that each instruction can be up to 32-bits wide. The x86 instruction set has been extended for 64-bit operation as the x64 instruction set.
All firmware and software—operating system, device drivers, and applications—must be specifically designed and compiled to run as 64-bit software. No 32-bit CPU can run 64-bit software. However, a 64-bit CPU can run 32-bit software.
ARM CPU Architecture
The principal alternative to the standard x86/x64 CPU architecture is one devised by Advanced RISC Machines (ARM) .
ARM do not manufacture CPUs. Instead, they produce designs that hardware vendors customize and manufacture. ARM designs are used in the current generation of Apple hardware, in most Android smartphones and tablets.
A typical ARM design implements a system-on-chip (SoC). SoC means that all the controllers—video, sound, networking, and storage—are part of the CPU. ARM designs use fewer, less complex instructions than is typical of x86. These features allow much better power and thermal efficiency, meaning longer battery life and the use of passive (fanless) cooling.
Simultaneous Multithreading
simultaneous multithreading (SMT), referred to as HyperThreading by Intel. A thread is a stream of instructions generated by a software application.
Most applications run a single process in a single thread; software that runs multiple parallel threads within a process is said to be multithreaded. SMT allows the threads to run through the CPU at the same time. This reduces the amount of “idle time” the CPU spends waiting for new instructions to process. To the OS, it seems as though there are two or more CPUs installed.
Symmetric Multiprocessing
This approach is to use two or more physical CPUs, referred to as symmetric multiprocessing (SMP). An SMP-aware OS can then make efficient use of the processing resources available to run application processes on whichever CPU is “available.”
This approach is not dependent on software applications being multithreaded to deliver performance benefits. However, a multi-socket motherboard is significantly more costly and so is implemented more often on servers and high-end workstations than on desktops.
The CPUs used in each socket must be identical models and specifications and must be models that support SMP.
CPU Cores
A single-core CPU has a single execution unit and set of registers implemented on a single package. A dual-core CPU is essentially two processors combined in the same package. This means that there are two execution units and sets of registers. Each core will also have its own cache plus access to a shared cache. This is referred to as chip level multiprocessing (CMP).
Multicore and multithreading features are designated by n C/ n T notation. For example, an 8C/16T CPU with multithreading support has eight cores but processes double that number of simultaneous threads.
Virtualization
A computer can be made more efficient and useful by configuring it to run multiple operating systems at the same time. This is achieved through virtualization software. Each OS is referred to as a virtual machine (VM).
Intel’s Virtualization Technology (VT) and AMD’s AMD-V provide processor extensions to support virtualization , also referred to as hardware-assisted virtualization. A CPU with virtualization support is required to run a virtual machine.
CPU Socket Types
CPU packaging refers to the CPU’s form factor and how it is connected to the motherboard.
Intel and AMD use different socket types , so you will not be able to install an AMD CPU in a motherboard designed for an Intel CPU (and vice versa). All CPU sockets use a zero insertion force (ZIF) mechanism.
LGA
Intel uses land grid array (LGA) socket form factor CPUs. The LGA form factor positions the pins that connect the CPU on the socket. The CPU is placed on a hinged plate and then secured to the socket using a locking lever.
PGA
AMD uses pin grid array (PGA) form factor chips predominantly. The PGA form factor positions the pins on the underside of the processor package.
The CPU is placed gently into the socket and then secured using a locking lever. Care must be taken to orient pin 1 on the CPU correctly with pin 1 on the socket so as not to bend or break any of the pins.
CPU and Motherboard Compatibility
Motherboards are specific to either Intel or AMD CPUs. Typically, motherboard compatibility is limited to the same generation of CPUs.
The CPU must be supported by both the physical form factor of the motherboard’s CPU socket and by the motherboard’s chipset.
There are limited opportunities to upgrade the CPU model while keeping the same motherboard, and such upgrades rarely offer much value.
