Intel Core i5-6400 vs Intel Core i7-7700K

The Intel Core i5-6400 (Skylake-S, 6th Generation) was developed for the mainstream desktop. The Intel Core i7-7700K (Kaby Lake-S, 7th Generation) targeted enthusiasts and gamers with high performance demands.

Both Intel CPUs are manufactured using the 14nm process and utilize PCIe 3.0. The Intel Core i5-6400 has 4 cores and 4 threads, 6 MB L3 cache, 34 GB/s memory bandwidth, and Intel HD Graphics 530. The Intel Core i7-7700K offers 4 cores with 8 threads (Hyper-Threading), 8 MB L3 cache, 38 GB/s memory bandwidth, and Intel HD Graphics 630.

In performance tests, the Intel Core i7-7700K significantly outperforms the Intel Core i5-6400 in both single-core and multi-core tasks. Its higher thread count and clock frequencies result in noticeably better computing power. For gaming, the Intel Core i7-7700K is the better choice.

Its superior single-core performance and Hyper-Threading enable smoother frame rates and a better experience in demanding games. The Intel Core i5-6400 is more energy-efficient with a 65 Watt TDP. The Intel Core i7-7700K has a higher TDP of 91 Watts, due to its performance and overclocking capabilities, which requires more robust cooling.

On the used market, the Intel Core i5-6400 is very affordable for basic systems. The Intel Core i7-7700K retains a higher used price thanks to its superior performance, especially for gaming, and offers better performance per euro for more demanding applications. The Intel Core i5-6400 is suitable for budget-conscious users looking for a stable processor for everyday tasks and light multimedia, who value energy efficiency.

The Intel Core i7-7700K is ideal for users who need high performance in games, demanding applications, and content creation, and who want to benefit from overclocking.