Not All Files Compress Well

It’s easy to assume that if you’re using good compression software, all the files you’re compressing will shrink by a fair amount. If only it were so simple. The fact is that some files compress much better than others. Audio, video and image file types come in various formats, some of which are already heavily compressed, while others aren’t. So while you shouldn’t expect to get much compression out of JPEGs, TIFF or RAW files can be squeezed down plenty, or WAV and AIFF files can compress quite a lot while MP3s can’t, so bear all that in mind.

Which Is the Best ZIP Software?

Popular opinion on this is split, but from our comparison between WinZip, 7Zip and WinRAR, 7-Zip came out marginally on top, taking into account the fact that it was free while you’d have to pay to use WinZip over the long haul. So for our guide, we’ll be using 7Zip.

How to Create a ZIP File

First up, download and install 7-Zip. Once you have it up and running, gather all the files you want to zip up into a single folder, ready for compression. Next, right-click that folder, click 7-Zip, then “Add to archive.”

In the 7-Zip window you’ll be presented with a whole bunch of options, and it’s worth having a general idea of what they do. Archive format: Out of the options here, 7-zip’s proprietary compression format, 7z, does the best job of compression, so we recommend using this. Note that whoever is unzipping this will need to also have 7-Zip installed. Compression level: Self-explanatory, really. To get maximum compression out of your files (at the expense of a longer compression process), select “Ultra.” Compression method: There are quite a few choices here, but the best one hands down is LZMA 2, particularly if your PC has a quad-core or stronger processor. LZMA 2 is the most modern method of compression out there and should be compatible with most modern systems. Dictionary size: Generally, the bigger the dictionary size, the more compression you get, but some users have said that this only applies up to a point. Up to 128MB you can make big gains, but above that it’s only incremental – you’re not saving that much space and are making the compression process longer. Word Size: Like Dictionary Size, the bigger the better in theory, but this is dependent on what kind of files you’re compressing so there is no universal rule. By default, word size will be 64MB if you’re using the LZMA or LZMA2 compression method, and that’s good enough. Solid Block Size: This bunches files of a similar size together, increasing compression even further. However, this will only make a notable difference if all the files you’re compressing are similar, which is unlikely. Best leave it as the default 4GB. With all these settings in mind, below are the settings I chose to compress my Morrowind mods folder.

Before hitting “OK” to start the zipping process, you can also choose to “Split to volumes” which will break your zip archive into several smaller ones, (They then need to all be in the same folder when you unzip them.) and you can also add encryption to your archive if security is a priority. When you’re ready, hit OK and let the zipping commence! Using the above settings, I compressed 1.1GB of all manner of mod-related files down to 398MB, which is pretty good if I say so myself.

Conclusion

With the above guide you should be up and zipping in no time, creating well-compressed files using what we consider to be the best zipping method available. Of course, so much of file compression depends on the actual files you’re compressing, so be aware that results may vary.