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What is MIPS (Million Instructions Per Second)?
MIPS or Million Instructions Per Second refers to the rough number of machine instructions performed by a CPU of the computer in one second. In simple terms, it indicates the speed of operation of a computer system as a whole.
- Million Instructions Per Second is the raw processing power of the computer and is mainly related to the speed of the Central Processing Unit.
- MIPS is a useful benchmark for comparing the performance of two processors that have similar architectures and when other factors are the same.
- This is a measure that gives a fair idea about the speed of performance of the CPU while dealing with a specific task rather than the instruction execution speed only.
- The MIPS measurement is also used by computer manufacturers, such as IBM, for determining the cost of computing per dollar.
- MIPS is easy to calculate and understand and helps in estimating CPI and execution time over and above the speed of the CPU, even for a large workload.
Understanding MIPS (Million Instructions Per Second)
MIPS is the rough value of the raw speed of the processor or the number of cycles completed by it in one second.
This helps in comparing the performance of two processors with the same architecture and operating in similar conditions.
Million Instructions Per Second value is also used to find the dollar value of computing. It is a common trend for different computer manufacturers, such as IBM.
In addition to that, MIPS also helps in estimating the average Clock Cycles Per Instruction or CPI and the execution time.
MIPS is very easy to determine and understand and can be used even if the workload is large.
However, MIPS can be misleading at times because it does not consider the different times that different instructions may take to be completed.
Also, the measurement technique should be different because different computers may need different sets of instructions to carry out the same activity.
Different instructions may take different times due to several factors such as:
- Memory amount and speed
- I/O speed
- Architecture of the processor
- Storage capacity and type
- Programming language used.
All these factors may make a computer perform much faster even with a processor with a lower MIPS rating in comparison to one that has a higher value of it.
Therefore, you cannot rely on the MIPS rating fully because this benchmark does not provide accurate information regarding the working of the processor, its speed and whether or not it is suitable for a specific application.
Also, now that gigahertz rules the computer industry, MIPS is less relevant.
So, you may not have accurate information about the real execution of the processor because, more often than not, even the simpler instructions may perform much better.
In a nutshell, MIPS is the older, if not obsolete, measurement of the operational speed and power of a processor.
Why is MIPS Not a Good Performance Rating for a Computer?
Ideally, there is no universal method by which the performance of the processor may be measured, certainly MIPS is not one. However, it provides just a rough estimate of the raw speed of the processor in the computer.
This is because it does not take the capability of the instructions, the I/O speed of the computer, the architecture speed of the processor and other factors into consideration.
Million Instructions Per Second is just a fair and older value to measure the performance of the computer processor.
It does not give an accurate picture of the capability of the computer because the value may vary for different programs run even on the same computer.
This is because there may be variable delay cycles for different CPUs based on the instruction priorities and capabilities.
MIPS may offer some interesting information but it is certainly not as descriptive as the manufacturers of the processors want it to be or for the users to believe.
Moreover, different architectures of processors such as the Complex Instruction Set Computer (CISC) and the Reduced Instruction Set Computer (RISC) have different rates, or MIPS, for executing a specific program.
This means that in such cases there is little or no relation of MIPS with their performance.
And finally, there are lots of things over and above the features and traits of the processor that may influence the performance level and speed of a processor while performing a calculation, which are also not taken into account by the MIPS measurement.
One such factor is the type of instruction being handled by the CPU. This will affect the eventual speed and performance of the CPU to a great extent, which will be even more profound if the architectures of any two processors in comparison are different.
This will have a notable impact, causing a significant difference in the MIPS rating of each processor, making it almost meaningless, literally.
Therefore, considering all of the above reasons, MIPS measures are not used much to measure the performance of the processors today.
How to Find CPU MIPS?
Usually, you can find the MIPS rating of a CPU by dividing the product of clock speed and the number of instructions performed by the processor in a single cycle by one million.
Therefore, the general formula for finding the Million Instructions Per Second rating of a processor is:
MIPS = (Processor clock speed * Number of instructions executed per cycle) / (10^6).
If a processor can carry out 8 32-bit instructions in a cycle and its clock speed is 1.2 GHz for each core, the MIPS of it will be – ((1.2 * 10^9) * 8)/(10^6) = 9600 MIPS per core.
Typically, you will need some specific inputs to calculate the MIPS of a processor. These are:
- The number of instructions performed by the processor in one second
- The speed of the processor or cycles per second such as 1 GHz, 2 GHz and so on
- The average Clock Cycles Per Instruction or CPI
- The execution time.
If you have only the execution time and the number of instructions performed by the processor, then you can calculate the MIPS of it by using the above formula.
Is Higher MIPS Better?
Yes, since MIPS denotes the number of millions of instructions performed by the processors per second, in general, the higher the number, the better it is for the performance of the computer.
A higher MIPS implies that the computer can do a larger amount of work. Typically, higher MIPS delivered per dollar will offer better value, especially for larger servers and mainframe computers.
Does Intel Use MIPS?
No, Intel does not use MIPS for measuring the performance of the processor.
Instead, Adjusted Peak Performance or APP and Giga Floating Point Operations Per Second or GFLOPS provide the information for the Intel processors.
Million Instructions Per Second is a very useful measure that gives a fair idea about the ability of the processors and the number of instructions that it can carry out in a given time.
However, there are lots of factors that the MIPS does not take into account, which makes it a less accurate and less reliable measurement.