Browse Prior Art Database

Program for Measuring CPU Operating Speed

IP.com Disclosure Number: IPCOM000080517D
Original Publication Date: 1973-Dec-01
Included in the Prior Art Database: 2005-Feb-27
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Greene, WB: AUTHOR

Abstract

The operating speed of a CPU is measured by initiating an external operation which has a reliable time duration and exercising the CPU by an internal iterative process which can be counted, or which involves counting. The total count over the known external operation period reflects CPU operating speed.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 83% of the total text.

Page 1 of 1

Program for Measuring CPU Operating Speed

The operating speed of a CPU is measured by initiating an external operation which has a reliable time duration and exercising the CPU by an internal iterative process which can be counted, or which involves counting. The total count over the known external operation period reflects CPU operating speed.

For example, CPU memory speed can be found through programming, by issuing a control command to any device which will cause an interrupt of a known time. A ribbon shift command to a typewriter could be used for this purpose. After issuing the shift, the program enters a counting process such as decrementing an index register or the like while waiting for the interrupt to occur. Upon receipt of the interrupt, the register count is checked to determine the time indicated for the response which determines the memory speed.

As a further example, assume that it is known that the time between the issuance of a typewriter ribbon shift command to the typewriter and the response back to the CPU in the form of an interrupt, indicating that the shift has been completed requires 50 milliseconds. After the interrupt occurs, the index register is checked to determine the memory speed. The faster memory speed would have decremented the index register to zero before the interrupt occured, and the slowest memory speed would leave the largest count in the index register at the time of the interrupt. Therefore, by subtracting a predetermined...