The SATA Express host connector is backward compatible with the standard 3.5-inch SATA data connector, allowing up to two legacy SATA devices to connect. At the same time, the host connector provides up to two PCI Express 3.0 lanes as a pure PCI Express connection to the storage device, allowing bandwidths of up to 2 GB/s.
Instead of the otherwise usual approach of doubling the native speed of the SATA interface, PCI Express was selected for achieving data transfer speeds greater than 6 Gbit/s. It was concluded that doubling the native SATA speed would take too much time, too many changes would be required to the SATA standard, and would result in a much greater power consumption when compared to the existing PCI Express bus.
SATA Express pinout
| Pin Number |
Pin Name |
Description | interface |
|---|---|---|---|
| S1 | GND | Ground | PCIe/SATA |
| S2 | PETp0/A+ | PCIe Lane 0 Host Tx / SATA Tx pair | PCIe/SATA |
| S3 | PETn0/A- | PCIe/SATA | |
| S4 | GND | Ground | PCIe/SATA |
| S5 | PERn0/B- | PCIe Lane 0 Host Rx / SATA Rx pair |
PCIe/SATA |
| S6 | PERn0/B+ | PCIe/SATA | |
| S7 | GND | Ground | PCIe/SATA |
| S8 | GND | Ground | PCIe |
| S9 | PETp1 | PCIe Lane 1 Host Tx pair |
PCIe |
| S10 | PETp1 | PCIe | |
| S11 | GND | Ground | PCIe |
| S12 | PERn1 | PCIe Lane 0 Host Rx pair |
PCIe |
| S13 | PERn1 | PCIe | |
| S14 | GND | Ground | PCIe |
| P1 | reserved | ||
| P2 | PERST# | PCIe reset | PCIe |
| P3 | CLKREQ# / DEVSLP | L1 PM substate / Device sleep |
PCIe/SATA |
| P4 | IFDet | Interface (PCIe/SATA) detect |
PCIe/SATA |
| P5 | GND | Ground | PCIe/SATA |
| P6 | GND | Ground | PCIe/SATA |
| P7 | V5 | 5 V power, precharge | PCIe/SATA |
| P8 | V5 | 5 V power | PCIe/SATA |
| P9 | V5 | PCIe/SATA | |
| P10 | GND | Ground | PCIe/SATA |
| P11 | DAS/DSS | Device Activity Signal / Disable Staggered Spinup |
SATA |
| P12 | GND | Ground | PCIe/SATA |
| P13 | V12 | 12 V power, precharge | PCIe/SATA |
| P14 | V12 | 12 V power |
PCIe/SATA |
| P15 | V12 | PCIe/SATA | |
| E7 | RefClk+ | PCIe common RefClk |
PCIe |
| E8 | RefClk- | PCIe | |
| E9 | ClkDet | PCIe RefClk detec | PCIe |
Pins E7,E8,E9 are optional.
Pins S7-S14 and P1-P4 are used in both motherboard and host cable connectors.
Additional signals in SATA Express host cable connector are derived from SATA power connector


