مقدمة في علوم الحاسب Lecture 5 Dr. Mai Elshehaly Department of Computer Science Faculty of Computers and Informatics Suez Canal University

Today’s Class CPU Speed: Presentations Internal Clock External Clock Superscalar Processor Pipelining Cores Presentations

Data Rates

Data Rates External Clock

External Clock Source: Santana, Gustavo AA. Data Center Virtualization Fundamentals: Understanding Techniques and Designs for Highly Efficient Data Centers with Cisco Nexus, UCS, MDS, and Beyond. Cisco Press, 2013.

Example: Pentium 4 Internal clock: 3.4 Ghz External clock: 200 MHz x 4 (QDR) = 800 MHz

Difference in speed External Clock ~800 Mhz Internal Clock ~3 Ghz

What can programmers do?

What can programmers do? Caching is your friend

Assume data is ready: Sequential processing (no pipeline) IF = Instruction Fetch ID = Instruction Decode EX = Execute MEM = Memory access WB = register Write back Usually < 1 instruction per clock cycle

Pipelining

Superscalar processing

Class Activity: Create a Car Steps: Draw a simple outline as I will show you Cut at the outline Fold the upper shape Draw 2 wheels and 2 windows

3 Teams Team 1  2 volunteers ( a processing unit and a time keeper) Team 2  5 volunteers (4 processing units and a time keeper) Team 3  5 volunteers (4 processing units and a time keeper) Team 1: Sequential Team 2: Pipelining Team 3: Superscalar

Time Recorded Team 1 Team 2 Team 3 Car 1 Car 2 Car 3 Car 4 Car 5

More speed? More transistors on the same chip  Moore’s Law

Is Moore’s Law dead? Pretty much yes!

Is Moore’s Law dead? Hello Multicore!

Dual Core

Intel’s Dual Core: http://www.computer-definition.com/dual-core.php

Intel’s Dual Core Processors Core 2 Duo Core i3

Core 2 Duo

Core i3

What is a thread? Program Process P1 Process P2 Threads

Threads in a Process

Sequence of instructions Thread Sequence of instructions

Superscalar processing: Instruction-Level Parallelism

Hyper-Threading: Thread-Level Parallelism Different colors = different processes Execution can happen for different threads (instruction sequences) on the same core https://en.wikipedia.org/wiki/Hyper-threading#/media/File:Hyper-threaded_CPU.png

Intel’s Quad Core Processors Core i5: Core i7:

Intel’s Quad Core Processors Core i5 Core i7 Hyper-Threading Turbo Boost

What is Turbo Boost?

What is Turbo Boost?

Q.E. USBكم عدد الاجهزة التي يمكن توصيلها بمنفذ واحد من نوع USB 1 ما هو اقصي طول للكابل مع USB 2 ما هو اقصي طول للكابل مع