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I have written code which performs a specific task; now when I will run on different machine(having different frequency) will it take different time?
Ouestion
If my code has one printf function, then will its required number of machine cycles be fixed for all machines, or will it depend on the system?
My system frequency is 2.0GHz, what does it mean?
The performance time of the code will depend on the frequency of the CPU, amongst many other things. All other things being equal, a faster CPU will take less time to execute the same instructions. But the number of other things that can affect the timing is vast, including O/S, compiler, memory chips, disk and so on.
If the machines have the same basic architecture, then the number of machine cycles is fixed. However, modern CPU architectures are very complex, and there could easily be variations depending on what else is running on the machine at the same time. If the machines have different chip types (even within a family such as Intel Core 2 Duo), then the results could be different. If the machines are of different architectures (Intel vs SPARC or PowerPC, say), then all bets are off.
If the ‘frequency is 2.0 GHz’, then it means that the main CPU clock cycles at 2.0 GHz. How many instructions are executed in that time depends on the instructions, and the parallelism (how many cores), and the CPU type, etc. The CPU frequency is separate from the bus frequency which controls how fast memory can be read (so, I’m using a 2.0 GHz CPU but the memory bus runs at 1067 MHz).