The charts below demonstrate the difference between Intel Core i7-4930K and Intel Core i7-3930K most important characteristics. These features, together with an IPC (instructions per cycle) number, determine how well a CPU performs. The "Number of cores / threads" graph displays the number of cores (darker area). Lighter area on the graph corresponds to the number of additional threads, provided by Hyper-Threading technology. The "Operating frequency" chart uses dark colour to represent base frequency, while lighter area is for extra frequency, provided by Turbo feature. Darker area on the "On-chip cache" graph is for the On-chip L2 cache. Lighter area is for the L3 cache.
Intel i7-4930k has a higher base clock rate than the 3930k as well as higher turbo frequency, moreover, the clock multiplier in the 4930k is 34 unlike the 3930k which is 32. Intel i7-4930k supports higher Memory data which goes up to DDR3-1866 unlike the Intel i7-3930k which supports Memory up to DDR3-1600 only.
Intel i7-4930k definitely performs more powerful than the 3930k as well as it runs at a much cooler environment due to the new manufacture process