Core i5-8400 is Intel's most affordable option to go beyond quad-core on the desktop. With a price point of $190 it is only half the price of Core i7-8700K, but delivers nearly the same performance in games and can also compete with Ryzen 6c12t processors thanks to its good single-threaded performance and high boost clock.
Slow computer got you down? Maybe a hardware upgrade should be in your cards, if so this guide to the Fundamentals of Upgrading a PC is an invaluable read. PCSTATS Tips