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Ankit malik
Ankit malik

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Goroutine vs OS thread


In the world of concurrent programming, two fundamental paradigms have emerged: goroutines and operating system (OS) threads. These concurrency models provide developers with different approaches to harnessing the power of parallelism and multitasking. Understanding the strengths and differences of goroutines and OS threads is crucial for building efficient and scalable applications. In this article, we will explore the concepts of goroutines and OS threads, highlighting their benefits and use cases.


  • Lightweight and concurrent units of execution in Go.

  • Advantages of goroutines:

    a. Lightweight and efficient compared to OS threads.
    b. Faster startup and lower memory consumption.
    c. Easy to create and manage with the "go" keyword.
    d. Ideal for concurrent programming and handling I/O-bound tasks.

OS Threads:

  • Higher Memory Footprint: OS threads typically have a larger memory footprint compared to goroutines due to their underlying system structures and management overhead.
  • Context Switching Overhead: Context switching between OS threads incurs additional overhead as it requires system calls. This can impact the overall performance and scalability of an application.
  • Suitable for CPU-Intensive Tasks: OS threads are better suited for CPU-bound tasks that require intensive computation. They can fully utilize the available CPU cores, allowing parallel execution of computationally intensive workloads.
  • Manual Thread Management: With OS threads, developers have to manually manage thread creation, synchronization, and load balancing, which can be more complex and error-prone compared to goroutines.


Aspect Goroutines OS Threads
Execution Model Lightweight and concurrent units of execution Lower-level concurrency abstraction
Memory Consumption Lower memory footprint nearly 4KB - 8KB Higher memory consumption nearly 1MB
Context Switching Overhead Faster context switching Higher context switching overhead
Task Type Well-suited for I/O-bound operations Suitable for CPU-bound tasks
Parallel Execution Enables parallelism and high concurrency Utilizes multiple CPU cores
Management Complexity Automatic scheduling by Go runtime Manual thread creation and synchronization
Resource Utilization Efficient utilization of system resources Resource-intensive and may require careful management
Scalability Good scalability for concurrent tasks Potential scalability challenges due to manual management
GOMAXPROCS Support Can be optimized with GOMAXPROCS setting Limited or no support for optimization

Maximizing Parallelism with GOMAXPROCS:

  • GOMAXPROCS Configuration: GOMAXPROCS is a configuration parameter in Go that specifies the maximum number of OS threads that can execute Go code simultaneously.

  • Default Setting: By default, GOMAXPROCS is set to the number of logical CPUs available on the machine, allowing Go to automatically utilize the available cores for parallel execution.

  • Performance Optimization: Developers can adjust the value of GOMAXPROCS based on the specific workload and hardware characteristics to optimize the performance of their applications.

  • Balancing Act: Setting GOMAXPROCS too high may lead to increased contention and context switching overhead. Finding the right balance is crucial for achieving optimal parallelism.


In conclusion, goroutines and OS threads offer distinct approaches to concurrency and parallelism. Goroutines, with their lightweight and efficient design, excel at managing concurrency and handling I/O-bound operations. They provide a higher-level abstraction that simplifies concurrent programming and reduces the complexity associated

Top comments (1)

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David Sugar

Goroutines do not tie into any priority scheduling, which is another simplification. In my eXosip cgo adaption, of course the realtime sip stack (in C) is using os/system threads, and the rest of the application layer is pure go. The two can be friendly and easy to use together where you have something with some real-time requirements this way.