NezSez writes regarding an article in extremetech:
"SATA Express is SATA and PCIe over cables (preserving backwards compatibility) and NVMe is the next improvement of AHCI with much lower latencies by using the PCIe bus/lanes. Both have been developed to improve access to SSD's which have their own processors on-board and can communicate quicker than mechanical drives. The specifications look good (up to 4 times faster and can scale with improvements of PCIe) but analysts suspect it will only be adopted for small form factors.
(Score: 3, Interesting) by wantkitteh on Monday March 17 2014, @03:22PM
I wasn't thinking so much about impedance as the drastic reduction in the conductor length (millimeters instead of meters) reducing signal noise.