Intel Core i7 990X Extreme
Starting off with the x264 video encoding test, which is very multi-core friendly, the Core i7 990X was 19% faster than the Intel Core i7 970 and 82% faster than the Core i5 2500K Sandy Bridge.
With the LAME MP3 encoding test, the Intel Core i5 2500K was the fastest and even beating out the $999 Core i7 990X. LAME isn't too multi-threaded friendly to take advantage of the extra cores (and Hyper Threading) of the i7 990X while the clock speeds between the i5-2500K and i7-990X are similar with the i5-2500K just coming up shy, but with this test the Sandy Bridge microarchitecture is of greater benefit. Even the Intel Core i3 2100 "Sandy Bridge" came in front of the Core i7 970 "Gulftown" processor.
7-Zip is an extremely multi-threaded test and as such, the two tested Gulftown CPUs were well ahead of the competition. The Intel Core i7 990X was about 17% faster than the Core i7 970 and 90% faster than the Core i5 2500K.