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This article mainly explains "must multithreading be more efficient than single threading in programming development". The explanation in this article is simple and clear and easy to learn and understand. let's study and learn "must multithreading be more efficient than single thread in programming development?"

First, what is serial? What is parallelism?

Serial: tasks are queued and executed one by one

Parallel: multiple tasks go hand in hand.

Second, the parallelism of single-core and multi-core.

Parallelism in the case of a single core: it is not really that multiple tasks are performed at the same time, it is necessary to switch back and forth between these tasks (that is, context switching).

Parallelism in the case of multiple cores: with several cores, several cores can really perform their respective tasks at the same time.

Third, the two types of tasks.

Compute-intensive tasks:

It is characterized by a large number of calculations and consumption of CPU resources, such as calculating pi, high-definition decoding of video, and so on, which all depend on the computing power of CPU.

Although this kind of computing-intensive tasks can also be accomplished with multiple tasks, the more tasks, the more time spent on task switching, and the lower the efficiency of CPU in executing tasks. Therefore, in order to make efficient use of CPU, the number of compute-intensive tasks simultaneously should be equal to the number of cores of CPU.

"IO intensive" tasks:

Tasks involving network and disk IO are IO-intensive tasks, which are characterized by low CPU consumption and spend most of their time waiting for IO operations to be completed (because IO (the process of reading content from the hard disk to memory, or the process of receiving information from the network to local memory) is much slower than CPU and memory.

For IO-intensive tasks, the more tasks, the more efficient CPU, but there is also a limit. Most common tasks are IO-intensive tasks, such as Web applications.

Fourth, after reading the above points, we can answer the question "will parallel execution be more efficient than serial?"

A: not necessarily, depending on the number of cores of the machine and the type of task.

1. If you are performing multiple compute-intensive tasks:

① single core: serial > parallel.

② multicore: parallel > serial.

two。 If you are performing multiple IO-intensive tasks:

① single core: parallel > serial.

② multicore: parallel > serial.

The advantage of using multithreaded programming on multicore or multi-CPU, or Hyper-threading-enabled CPU is obvious, that is, it increases the execution throughput of the program.

On single-CPU or single-core computers, using multithreading technology, we can also separate the blocking part of the process responsible for Icano processing and human-computer interaction from the part of intensive computing, and write special workhorse threads to perform intensive computing, thus improving the execution efficiency of the program.

Thank you for your reading, the above is the content of "must multithreading be more efficient than single threading in programming development?" after the study of this article, I believe you must have a deeper understanding of the problem that multithreading must be more efficient than single threading in programming development, and the specific use still needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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