Multi-threaded file download for Linux

Does Linux have multithreading?

Yes, Linux has multithreading capabilities. In Linux terminology, this feature is known as simultaneous multithreading (SMT) or Hyper-Threading. With multithreading enabled, a single core on the hardware is mapped to multiple logical CPUs on Linux. This allows multiple threads to simultaneously issue instructions to a core during each cycle.

Multithreading allows a single physical processor to appear to have multiple virtual processors, each executing parallel threads of code. It provides a performance boost by allowing multiple threads of execution to run concurrently, improving system efficiency and reducing overall latency.

In Linux, the implementation of multithreading depends on the processor architecture. Some processors, such as Intel Pentium processors, support SMT, while others, such as AMD Athlon processors, do not. Linux distributions typically detect the SMT support provided by the processor and configure it accordingly. When multithreading is enabled, each logical CPU can execute multiple threads simultaneously. This allows the operating system to allocate threads efficiently, taking advantage of the available processing power. By interleaving the execution of multiple threads, multithreading can improve overall system throughput and responsiveness.

Axel - A Download Utility for Improved Speed and Support

Axel is a download utility that aims to enhance the download process by efficiently utilising multiple connections for a single file. Developed by a team of talented developers, Axel claims to boost download speeds by up to 60%.

One of the key features of Axel is its extensive support for various protocols, including HTTP/HTTPS, FTP, and FTPS. This flexibility allows users to download files from various sources, ensuring compatibility with a wide range of download options.

With Axel, users can enjoy the convenience and efficiency of downloading files at lightning-fast speeds. By utilising multiple connections simultaneously, Axel significantly reduces waiting time and improves the overall download experience.

To ensure optimal performance, Axel employs advanced algorithms and techniques to optimise resource allocation and mitigate any potential bottlenecks during the download process. This attention to detail ensures that users get the best download speeds possible.

In addition to speed enhancements, Axel also offers a wide range of features to enhance the overall download experience. This includes support for resuming interrupted downloads, the ability to prioritise downloads based on file type or content, and the ability to pause and resume downloads at any time.



apt install axel


yum install epel-release && yum install axel


dnf install axel

To perform a simple load using Axel, you can use the following command:


The -a option is used for an alternative progress bar:

axel -a

You can set the maximum download speed with the corresponding option -max-speed or short -s. The value is set in bytes per second.

axel --max-speed=512000

To save the file under a different name, you can use the -o option to specify the file name:

axel -o gigabyte.test

Specify the maximum number of connections using the appropriate -n option :

axel -n 10


This is a utility for downloading files. Supported protocols are HTTP(S), FTP, BitTorrent and Metalink.

How does aria2 work?

aria2 uses the concept of BitTorrent to create a distributed downloading network. Instead of relying solely on a single connection, aria2 divides the download task among multiple connections, which significantly speeds up the download process.

Features of aria2

  • Highly Customizable: aria2 offers a wide range of customization options to fit your specific needs. You can define the number of connections, download speed limits, and more.
  • Resume and Retry: If the download link or connection breaks during the download process, aria2 can automatically resume the download from where it left off.
  • File Integrity Check: aria2 provides a feature to verify the downloaded file's integrity. This ensures that the file has not been tampered with during the download process.
  • Secure Connections: aria2 supports secure connections, such as HTTPS and FTPS. This helps to protect your download from eavesdroppers and unauthorized access.
  • Torrent Support: In addition to downloading files over HTTP, aria2 also supports downloading torrents. This helps to download large files efficiently from tracker websites.

Installing aria2

To upload a file, Aria2 can use different sources/protocols and tries to use the bandwidth as much as possible.


For Ubuntu/Debian

apt install aria2

For CentOS/RHEL:

yum install aria2

For Fedora:

dnf install aria2

To perform a simple boot with Aria2, you can use the following command:


Uploading a file from 2 different HTTP servers:

aria2c "" ""

Downloading a file simultaneously from an HTTP server and an FTP server :

aria2c --ftp-user=<USER> --ftp-passwd=<PASSWD> "<a href="ftp://" class="redactor-autoparser-object">ftp://<FTPSERVER/IP>/<...;" ""

Downloading a file from one host, using 2 connections:

aria2c -x2 -k1M ""

You can specify the number of concurrent downloads with option -j :

aria2c -j2

Downloading a file from an FTP server :

aria2c --ftp-user=<USER> --ftp-passwd=<PASSWD> "ftp://<FTPSERVER/IP>/<FILE>"


aria2 is a powerful and user-friendly download utility for Linux users who need to download large files efficiently. With its support for multiple connections, resume and retry functionality, file integrity check, and secure connections, aria2 provides a seamless and efficient download experience. So, next time you need to download a file, consider using aria2 to speed things up!