Some of the main features of 7z format are:
Compression ratio results are very dependent upon the data used for the tests. Usually, 7-Zip compresses to 7z format 30-70% better than to zip format. And 7-Zip compresses to zip format 2-10% better than most of other zip compatible programs.
Benchmark Results: 7-Zip relies heavily on multiple threads and cores. The AMD Phenom II X4 980 Black Edition is one of only two true quad cores without extra threads. The AMD Phenom II X4 980 Black Edition was able to decompress 14933 MIPs and compress 12884 MIPs.