The Intel Core i5-9400F is a six-core desktop processor based on the Coffee Lake architecture introduced in October 2018 along with the flagship Intel Core i9-9900K. The processor clocks at 2.9-4.1 GHz and can process up to 6 threads simultaneously. The Intel Core i5-9400F is manufactured in the improved 14-nm process (14nm++).
Compared to the Intel Core i5-8400, the performance could only be increased slightly. Performance increases of up to 10 percent can be expected. Both processors (old and new) still do not offer hyperthreading. The performance increase therefore only adds up to small architecture improvements and a slightly higher basic and turbo clock rate. This CPU is suitable for everyday office use, which does not require large coolers due to the low waste heat. But games are also among the application areas, because in games the Intel Core i5-9400F clearly beats the Intel Core i3-9100F. Here the six cores are paying off in the meantime.
The Intel Core i5-9400F is a processor without integrated graphics unit. If you value an iGPU, you should take a closer look at the Intel Core i5-9400, as it offers the entry level Intel UHD Graphics 630.
Intel puts the Thermal Design Power (TDP) at 65 watts. This means there is no need for large cooling systems, which also allows installation in very compact housings.