DDR3L differs from traditional DDR3 as it runs at 1.35V rather than 1.5V. This means it consumes less power and runs cooler. DDR3L is required for Intel Skylake CPUs using the Z170 chipset. For the best performance choose a pair of DIMMs running together in dual-channel mode at the highest frequency you can afford. These are the entry-level kits, with speeds between 1,600MHz and 2,133MHz.