Help
Bandizip in comparison with other archivers
How to use Multi-core Compression
How to use the Finder’s right-click menu for Bandizip
How to set Bandizip as the default app to open archives
How to open ALZ and EGG files on Mac
How to use Extract Here (Smart)
How to split a large file into smaller files with Bandizip
How to view a list of files in an archive
How to modify an archive without decompression
How to set a password for an archive
How to encrypt filenames in archives
How to preview image, document, and music files in an archive
How to move files to Recycle Bin (Trash) when deleting
How to use presets when compressing files
How to use Parallel Extraction
How to use the Password Manager
How to use the Auto Password
How to use Repair Archive
How to use the Password Recovery
Troubleshooting
How to troubleshoot when codepage auto-detection doesn’t work correctly
How to troubleshoot when Error 22 occurs and Mac Finder on Catalina can’t extract a ZIP archive
How to troubleshoot when a split archive can’t be decompressed
How to troubleshoot when an extracted app file can’t be opened
How to troubleshoot when it takes too long to open archives
How to troubleshoot when a badge icon for files doesn’t appear in the Finder
How to troubleshoot when the Finder displays for external volumes incorrectly in the sidebar
How to troubleshoot when I can’t uninstall Bandizip
How to troubleshoot when I can’t install Bandizip on the App Store
How to request a refund for Bandizip that you bought from the App Store





How to use Multi-core Compression

What is Multi-core?

A core is a processing unit in a CPU, and a CPU with two or more cores is called a multi-core CPU. Multi-core CPUs have become very common these days. Four or eight-core CPUs are widely used, and even CPUs for mobile devices are made as multi-core CPUs. Therefore, whether a software product supports multi-core CPUs is an essential factor in evaluating its performance.

Multi-core Compression

Bandizip supports multi-core compression. Since data compression requires a lot of CPU work, using multi-core helps to improve the compression speed.



For example, Bandizip compresses your file(s) 6 times faster with 4 cores 8 threads CPU, and 13 times faster with 8 cores 16 threads CPU.

The pictures below show the comparison between Bandizip that supports multi-core and Mac Finder that only uses single-core.




Why is multi-core not used during decompression?

You may find that compression by Bandizip increases the CPU usage to the maximum, but decompression does not increase the usage that much.

This is due to a characteristic of data compression algorithms. When decompressing an archive, most algorithms should access the front data of the archive first. Unlike compression, therefore, decompression is difficult to be processed in parallel by a multi-core CPU. Even with a large number of cores, the processing speed hardly improves.

Thanks to the recent advancement of technology, however, some ways have been introduced to make full use of a multi-core CPU when decompressing an archive. Bandizip may perform faster decompression using every core in the CPU for the following archives:

  • 7Z archives compressed with LZMA2 algorithm
  • RAR archives compressed with RAR5 algorithm
  • ZPAQ archives
  • ZIP archives

Why is CPU usage not high during compression?

There may be a problem that compression doesn’t increase the usage either. Compression is processed by the following steps:

Reading the file to compress (Storage) ▶ Compression (CPU) ▶ Writing to the archive (Storage)

In general, a bottleneck occurs during the compression, resulting in high CPU usage. However, in some cases, such as using slow-speed media (external USB drive, network drive, etc.) a bottleneck occurs on storage I/O and therefore CPU usage is not high.

Note

  • When you compress multiple files of small size (less than 100KB) the speed improvement is minimal even with multi-core.
  • 7zip supports multi-core compression when compressing your file(s) in ZIP format, but it works only for multiple files and not for a single file.