Archive Comparison Test - by Jeff Gilchrist
(DOS/Windows & Macintosh Edition)


August 9, 2007

I have updated the JPEG test with the new version 2.2 of packJPG, the free lossles JPEG compressor.  This release is both faster and compresses better than before.  The only issue is that uses a new format so the JPEG files compressed with an older version of packJPG are not compatible with this new release.  You can see the latest results here.

May 7, 2007

Hello everyone, I'm not dead just been very busy with family life and school.  Not long after the last update in 2005, our first child was born, followed by me finishing my Masters degree, followed by me starting a PhD, and just last month our second child was born.  I had a few minutes to add another JPEG compressor from Germany, this one is a pre-public version of packJPG written by Matthias Stirner.  PackJPG so far gives the best JPEG lossless re-compression for a non-commercial application.  Stuffit's new JPG compression still beats it, but you will soon have an open source alternative.  I am told packJPG will eventually be released as open source and will be available for Linux and Windows along with a GUI. You can see the latest results here.

Mar 19, 2005

As Allume promised, the JPEG compression technology was be rolled into the new version of Stuffit. I have just received a beta copy of Stuffit Deluxe 9 and ran it through the JPEG test. I'm happy to see that they have greatly improved the speed of the algorithm. The version of the JPEG compressoin algorithm in Stuffit 9 is between 2 and 4 times faster depending on the compression options you choose. Another interesting feature is that you can store thumbnails of the JPEG images right in the stuffit archive so you easily determine which pictures to extract at a later date. Adding thumbnails increases the size of the archive but its less than 1%. You can see the latest results here.

Jan 9, 2005

I am still extremely busy with working and doing my Masters degree so no full updates to ACT yet unfortunately. My Masters thesis is related to data compression though and you can see the latest software I have developed over here. I did get a chance to try out some new compression technology that has the ability to losslessly compress already-compressed data. The first use of the algorithm is for JPEG files, so you can compress your digital camera pictures even further without losing any quality. On average the algorithm gives 30% compression, and in my testing it did about 25%. I have setup a special page for you to see some results here.

Feb 13, 2004

Just wanted to let everyone know that I am still alive. ;) I have been so busy with working full time and doing my Masters degree at the same time I really haven't had any spare time to work on A.C.T. lately. I hope to start publishing results again, just not sure when at this point. Note, that since I have been getting so much spam on my old email address, I have updated it to something new (look at the bottom of the front page).

Oct 7, 2002

Happy Birthday ACT! Its hard to believe but I first published ACT ten years ago. As usual, it has been a busy time for me, even more so than usual. I recently got married and I also started doing my Masters degree (while continuing to work full time).

I have updated the Macintosh section of ACT with the new release of Stuffit Deluxe 7.0. This is a major new release on the Mac platform. It includes support for the new SITX format which uses the PPM and BWT algorithms to get smaller compressed files. This is one of the few commercial packages using advanced compression algorithms like these. They have also added support for error correction so you can recover from corrupted data and it supports archives larger than 4GB. Included now is support for real encryption algorithms such as RC4, Blowfish, AES, and Triple DES. The RC4 algorithm is the one exposed in the GUI but the rest are available from the OSX command line version. The rest should be available in the GUI in a future release. The compression algorithms for their BZIP2, GZIP, and ZIP formats have also been tweaked and give better performance often with faster speeds too.

May 12, 2002

I have finally updated the DOS/Windows section of ACT. I have a number of new programs that people have been asking for and it seems that many of the major playors have new updated compression algorithms to show off. I have also added compressed versions of many of the larger HTML pages. You can just click on the graphics on various pages to view the HTML compressed version of the web pages. These are much smaller, will download much faster, and automatically render in most HTTP 1.1 browsers. For example, the act-index.html page is normally 200k and the compressed HTML version is only 11k which makes a huge difference in download time!

New programs tested for the DOS/Windows version this month:

MONKEY'S AUDIO 3.96 RAR32 (DOS) 3.00b5 RAR (Win32) 3.00b5 RKAU 1.07
WINACE 2.11      

I still have a number of other archivers to test so I will post my current queue of programs so that you can see what is coming in the future: 7ZIP, ARJ, ASPACK, AUDIOZIP, BZIP, DZIP, EXE32PACK, GCA, IMP, INFOZIP, PAR, PECOMPACT, PKZIPW, SZIP, UHARC, UPX, WINIMP, ZZIP

March 8, 2002

Sorry for the long delay in an update. I have been more busy than expected planning this wedding, and doing wedding related things almost every day since Christmas. My computers were also down for a month or so which didn't help. I'm not sure when the next update of ACT will be out but definitely not in the next couple of weeks. On the main page, a friend of mine Chris has animated the logo that another Chris made for me. What do you think?

October 2, 2001

I have updated the Macintosh section of ACT. Most of the coding for the new ACT web site has been completed by Chris, now he is mostly just waiting on me doing a lot of data entry to get the ACT info into the MySQL database. I am now engaged to be married so spending a lot of time planning the wedding and I will also be moving this month so it will be a bit of time before I can get to the data entry.

New programs tested for the Macintosh version this month:


September 11, 2001

My heart goes out to all those people who lost family and friends in the tragic events of September 11th, 2001.

June 24, 2001

Yes it is true, ACT has actually been updated! Welcome to ACT's new permanent home on the Internet. My e-mail address has also changed, so for any correspondence related to ACT, please use: ACT e-mail address

The site redesign is taking much longer than I had anticipated so I have decided to launch to new domain and update the archiver information before all the new features are ready. Over time, the site will look quite different and have many new features since we will be able to generate dynamic content using PHP and mySQL. Since the site will be using server-side scripting and databases, I will no longer be using free web providers as mirror sites since they cannot offer such services (besides you were probably annoyed by all the pop-up/banner ads they show). The other nice benefit of the changes will be that I will just have to enter the data into the database and it will do the rest for me which means MUCH more frequent updates.

New programs tested for the DOS/Windows version this month:

BA 1.01 RAR32 (DOS) 2.80 RAR (Win32) 2.80
RK 1.04.1 SBC 0.860 YBS 0.03e

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