With the launch of Coffee Lake, Intel's Kaby Lake products have started the slow march towards exiting the market. But there is still value in the aging platform, and the 200-series chipsets and the associated Kaby Lake processors still offer a lot of performance for your everyday needs.
Intel's Z270 chipsets is the most feature rich solution for Kaby Lake processors. It is nearly identical in every detail to the newer Z370 chipset, but it does not support the newer Coffee Lake CPUs, despite sharing the same LGA 1151 socket. Compared to the other 200-series chispets, Z270 has more HSIO lanes, PCIe lanes, and USB 3.0 ports, and it is the only 200-series chipset that supports overclocking CPUs. The Z270 chipset is also the only 200-series chipset that can divide the CPU's PCIe 3.0 lanes between multiple graphics cards.
Motherboards have dozens of specs that may vary from one board to the next, but there are four key variables that outweigh the rest: CPU, chipset, memory, and power delivery system. Now, depending on your own specific uses, other factors such as the USB support or networking options may be prioritized, but the importance of these other features will vary considerably from one person to the next, whereas everyone should carefully consider the four key variables.
Typically, you first decide if you want to build your new PC around an AMD or an Intel CPU. Next, you'll need to pick a chipset based on its feature set and price. Because this article is focused on Z270 motherboards, we will proceed under the assumption that you've selected an unlocked Intel Kaby Lake processor and the Z270 chipset. If you don't plan to overclock, you may want to consider a lower-end chipset and CPU.
You should also consider the system's memory support. Unless you're building a compact PC, you want to have four DIMM slots to support higher quantities of memory. The maximum memory frequency is also important if you plan to use high-performance DDR4. Officially, Kaby Lake only supports DDR4 at speeds up to 2400MHz, but a Z270 motherboard may support DDR4 DIMMs operating at speeds of 4233MHz or higher.
When selecting a Z270 motherboard, it's crucial to pay attention to the power delivery system, especially if you plan to overclock. An insufficient number of power phases or inadequate cooling can limit your overall system performance and cause the CPU to throttle. In general, a greater number of power phases and larger heatsinks over the MOFSETs, the better. While eight phases is typically sufficient for most, boards with more may produce better overclocking results.