Apple's new M6 and M5 Pro Mac mini models return to soldered NAND storage, eliminating the upgrade capability that was available in M4/M4 Pro models. Additionally, 256GB configurations use a single NAND chip, resulting in slower SSD speeds compared to 512GB+ models, though still faster than previous generations.
Apple Silicon chips (M2 through M5) achieved approximately 50% single-core performance improvement over three years, driven primarily by increased CPU frequency (3.5 to 4.6 GHz), higher instructions-per-cycle decode width, additional efficiency cores, and significantly improved memory bandwidth (154 GB/s on M5 versus 100 GB/s on M2). The newer M6 chip adds further performance gains through additional cores and bandwidth increases.