The Core i5-8400 is a six-core CPU with six threads, 2.8 GHz base clock and 4.0 GHz maximum clock, being one of the mainstream models from Intel’s eighth generation of Core i CPUs. Let’s see how fast it is.

The new eighth generation of Core i7 CPUs from Intel, codename Coffee Lake, was recently launched with the new Z370 chipset. In this new generation, the microarchitecture is very similar to the previous one (Kaby Lake), with the same graphics engines, same supported technologies, and the same 14 nm manufacturing technology. The biggest difference is the CPU core count: while, on previous generations, Core i7 CPUs had four cores and eight threads (thanks to the Hyper-Threading technology), Core i5 had four cores and four threads, and the Core i3 had two cores and four threads, on the eighth generation Core i7 CPUs have six cores (and 12 threads), Core i5 processors have six cores (and six threads), and Core i3 CPUs now have four cores (and four threads, as they lose HT technology).

It may be motivated by the launch of AMD Ryzen processors, that bring more cores than Intel counterparts, with similar single core performance. The tendency of the industry is to offer a higher core count on desktop CPUs, and we can expect programs and games to take advantage of the extra cores in the near future.

Keep in mind that, even if the socket used by the eighth generation CPUs is physically the same used in the sixth and seventh generations (LGA1151), the pin disposition is not exactly the same, allegedly to meet the higher power demand of the new CPUs with more cores. Because of this, sixth and seventh generation CPUs do not work in motherboards designed for the eighth generation ones (that use 300-series chipsets), and vice-versa.

The Core i5-8400 is the most basic CPU of the new Core i5 family, being aimed at cost/benefit-oriented desktop computers for gaming or working. It has a base clock of 2.8 GHz and a maximum Turbo clock of 4.0 GHz, with 9 MiB of L3 cache. It has a TDP of 65 W and brings Intel UHD 630 integrated video running up to 1.05 GHz.

Figure 1 shows the Core i5-8400 CPU. It is sold with a cooler, but we received the CPU sample only.

Core i5-8400Figure 1: The Core i5-8400

In Figure 2 we have the underside of the CPU.

Core i5-8400Figure 2: Underside of the Core i5-8400

For our benchmarks, we compared the Core i5-8400 to the Ryzen 5 1500X (review here), which is its direct competitor, and to the Core i5-7400 (read about it here), which is the CPU to be replaced in the market by the Core i5-8400. We also included the Core i7-8700K (review), the Ryzen 7 1700X (read review here), and the Core i7-7700K (review).

We used a GeForce GTX 1080 video card on all tests.

Let’s compare the main specs of the reviewed CPUs on the next page.