This time around, Intel has finally brought a six-core/12-thread chip into the U-series family, the Core i7-10710U. That processor will feature a base clock of 1.1GHz, a single-core Turbo speed of 4.7GHz and all-core Turbo at 3.9GHz. Stepping down to the next model, the i7-10510U, you'll get higher speeds (1.1GHz base; 4.9GHz single-core Turbo; 4.3GHz all-core Turbo) but only four cores and eight threads.
Intel says the i7-10710U is 16 percent faster than last year's i7-8565U overall (the 9th-gen CPUs were focused on gaming laptops), and 41 percent faster when it comes to productivity and multitasking in Office 365. That's a significant leap, but I wouldn't rush to upgrade a year-old laptop. Even though these are all 10th-gen chips, since they're based on the 14nm production process, they won't get the speedy Iris Plus graphics found on the first batch of 10nm 10th-gen processors.
As usual, the U-series chips are meant for mainstream ultraportables like Dell's XPS 13, while the Y-series are targeted at even slimmer machines and 2-in-1s. Those Y-series chips are also getting beefier this year, as every model except the i3 will offer four cores, eight threads and boost speeds beyond 4GHz. I've always found Y-series chips a bit too sluggish to use in a primary machine, but that might actually change this year.