Thanks for this review, but I cannot agree with your results, because mine are staggeringly different!
Here are some stats from a comparison I did myself, on a scenario of some files, that are being compressed and sent to a backup-server on the Internet every single day. This is, in effect, a real practical example and not some random test data, which may or may not show the same characteristics as many of the available benchmarks.
The data from my tests may not be as scientifically accurate as yours in this review, mainly because this is not a clean workstation and the files were both read from and written to the same HDD, I fully understand that fact. But the results are still so significantly different, that some minor deviations from the hard-drive performance or background applications like an idle browser or the deactivated Avast! won't make much difference to the results.
The hardware and operating system used in my test:
Windows 7 SP1 64-bit
Intel i5-2500K (turbo deactivated, all 4 cores at 3.7 GHz)
16GB Kingston DDR3-1333 CL9 RAM
The programs I used:
WinRAR 4.20 64-Bit
7-Zip 9.30 alpha
The files I compressed:
962 files, total size 614.87 MB, average size ~ 655 KB
types are html, js, php and cgi in that order
The WinRAR settings I currently use:
rar, best compression, solid archive, lock archive, force text compression, 1024 KB dictionary size
The 7-Zip settings I tried (all with 4 threads):
a) 7z, ultra, lzma2, rest default values (32 MB dictionary, 64 word size, 4 GB block size)
b) 7z, maximum, lzma2, solid block size, rest default values (32 MB dictionary, 64 word size)
c) 7z, maximum, lzma2, 8 MB dictionary, 32 word size, solid block size
The results of the compression tests:
WinRAR - 125.62 MB - 2:12 minutes
7-Zip a) - 142.21 MB - 5:10 minutes
7-Zip b) - 144.48 MB - 4:33 minutes
7-Zip c) - 149.99 MB - 3:00 minutes
In the end, WinRAR is both one third faster than the fastest 7-Zip settings I used and it creates an over ten percent smaller archive than the smallest alternative file.
Maybe there is some unknown "golden setting" that I could achieve, by playing around with the dictionary, word and block sizes in 7-Zip. If someone knows of certain settings, that would work better than mine did for text-only files with a target compression rate of 20 percent, I would be grateful to hear about it.
As it stands though, I am very happy with my WinRAR.