File compression basics
Overview
When it's all said and done, I prefer 7-zip over everything else. It has the best compression, it's free, the source code is freely available and you can decompress all archives and create 7z or zip archives.
If you want the best compression to save space, download and upload time, use the .7z format.
If you want the best speed during compression and best portability, use the .zip format. (good for small files so that even WinXP can open them)
The .rar format is simply a middle-of-the-road format.
Most common archive formats (2010)
- Filetype extension: .7z*
- Commonly referred to as: 7-zip (or SevenZip)
- Program Web site: www.7-zip.com, File Mirror + Documentation @ TESNexus
- Cost: FREE
- License: Open Source, GPL
- Compression: Best
- Portability: To extract files in this format, each use must have 7-zip or the latest version of WinRAR
- Native Support in Windows XP?: No
- Filetype extension: .rar
- Commonly referred to as: RAR
- Program web site: www.rarlabs.com
- Cost: $30
- License: Trialware
- Compression: Better than OK
- Portability: To extract files in this format, each user must have WinRAR, 7-zip, or simular compatible program.
- Native Support in Windows XP?: No
- Filetype extension: .zip
- Commonly referred to as: Zip
- Program Web Site: www.winzip.com
- Cost: $35
- License: Trialware
- Compression: OK
- Portability: This format has been around so long that just about every program that deals with compression can handle it.
- Native Support in Windows XP?: Yes
Compression size comparison
- Oblivion Mod to compress: Apophis: Armory of the Silver Dragon 0.9.3
- Oblivion Mod uncompressed size: 151 MB
- Archive Program: 7-Zip v4.65
- Compression Setting: Maximum
- Time to Compress: 0 minute, 33 seconds
- Time to Decompress: 0 minute, 5 seconds
- Final compressed size: 55.5 MB
- Archive Program: WinZip v14.5
- Compression Setting: Best Compression (non-compatible)
- Time to Compress: 0 minute, 59 seconds
- Time to Decompress: 0 minute, 7 seconds
- Final compressed size: 63.2 MB
- Archive Program: WinRAR v3.93
- Compression Setting: Best
- Time to Compress: 0 minute, 13 seconds
- Time to Decompress: 0 minute, 3 seconds
- Final compressed size: 74.5 MB
- Archive Program: WinZip v14.5
- Compression Setting: Legacy (Zip 2.0 compatible)
- Time to Compress: 0 minute, 40 seconds
- Time to Decompress: 0 minute, 4 seconds
- Final compressed size: 75.5 MB
NOTE: The above results were from using the 32-bit versions of the programs on a Windows 7, 64-bit operating system.