The newest iMac to hit the market, with an Intel 3.4GHz Intel Core i7 processor and 256GB SSD option, is officially the fastest mac ever shipped. It even beat out a Mac Pro XEON 6-core.
This generation's iMacs were the first to have an SSD option, and the speed boost shows in the benchmarks. While doing individual application tests like exporting mp3s and running Photoshop, it handily bested its competition. It was in more processor-intensive tests like running Mathematica and and Cinebench that the configuration fell to the Pro model, and that was only because those programs benefit from multiple cores.