CPU Performance Equation contd.

Structured Computer Organization (4th Edition)

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
Image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Linfominatelgir+ it is difficult to change one parameter in complete isolation from others hewuse the basic technologies involved in changing each character— istic are also interdependent: I Einst- cycle rims—Hardware technology and orgardsatinn - CPI—Organisation and instruction set architecture I Instructien count—Instruction set architecture and compiler technology Luckily. many potential performance improvement techniques primarilyr improve one component of CPU performance with small or predictable impacts on the other two. Sometimes it is useful in designing the CPU to calculate the number of total CPU clock cycles as 1| CPU clock cycles = E can ME]. [I 1 where 1C;- represems number of times instruction i is executed in a program and CPL- represents the average number of clock cvcles fnr insn'uctinn l. This form can heused tn express CPU time as 11 CPU time = [ Z EPlix lflr] xCInclt cycle Lime t - l and overall CPI as l'l Sentinel. int i" ( 1C: 1 CH - Distinction count - Z CPII-X Insmiefinnenunt i=1 The latter form of the CPI calculation multiplies each individual CPI; by the frac- tinn cf occurrences of that instructicn in a program CPI; should be measured and not just caieulntetl from a table in the hack of a reference manual since it must inr elude cache misses and any flfl'ilfl' memnqr system ineffieiencies. Consider our earlier example, here modified to use measurements of the fre- quency of the instructions and of the instruction CPI values. which in practicct are easier to obtain. ...
View Full Document

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern