The letter at the end of the chip name (“U” in our example) is Intel’s designation for the chip’s purpose. For laptops, the letters you’ll see at the end are Y, U, and H . The only one you need to worry about are the Y series chips, which are optimized for battery life. That’s good if you’re frequently away from a plug for long periods of time, but that added battery life comes at the expense of some performance. H chips are optimized for performance, and U chips are “power efficient” but not “extremely” efficient like the Y line.
AMD’s chip naming is just as difficult to decipher as Intel’s.
In the name AMD Ryzen 5 7600X, the “7” is the generation (how old it is; higher is better), and the “6” is how powerful it is. A “6” would make this example a medium-powered chip, whereas a 3 or 4 would be weaker (slower). The next two numbers don’t have much impact on anything. The “X” at the end indicates high performance. Other letter designations include U for ultra-low power.