Reading the CPU clock cycles to measure performance

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With the Pentium, Intel finally introduced a benchmarking function for their CPUs.

RDTSC - Read Time Stamp Counter

RDTSC returns the number of clock cycles since the CPU was powered up or reset. It can be used for benchmarking without repeating your code thousands of times.

Below is a quick Delphi function that will read the CPU's clock cycle count and return it as a 64bit integer. As said above, this works on a Pentium and higher, meaning 486 CPUs do not have this instruction.

	// Returns 64-bit count of CPU clock cycles. function GetCpuClockCycleCount: Int64; asm dw $310F // opcode for RDTSC end;

Comments:

2005-11-16, 20:26:59

kn-hh@web.de from Germany

yes - works much quicker than QueryPerformanceCounter. if I only knew, how to find out the frequency of the cpu (ticks/second). of cource i know the frequency of my cpu, however if the program is running on another pc .... Any ideas ? thanx/regards, klaus

2007-03-12, 19:35:12

raygurlz@gmail.com from Australia

can you please find other measures of a computer’s speed besides the clock cycle? Keywords: junk

2007-03-18, 19:54:07

anonymous from Australia

yeah you can connect to a fucking note from the internet malo mata'usi Keywords:

2007-04-30, 23:58:13

piza-cake from United States

If you want to determine CPU speed find - > function GetCPUSpeed in - > JclSysInfo.pas of Project JEDI Code Library (JCL) Keywords:

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