New NVMe spec brings new support for hard drives

The first flash-based SSDs used SATA/SAS physical interfaces borrowed from existing hard drive-based enterprise server/ storage systems. However, none of these interfaces and protocols were designed for high-speed storage media and the SATA/SAS bus became a bottleneck for the much faster SSD. The initial fix was SSDs on a PCI Express (PCIe) card. While much faster, PCIe was also proprietary and meant as a point-to-point transfer. A PCIe SSD in one server could not be directly accessed by any other server, it had to go through the system bus, adding all kinds of latency.