The above diagram shows the 2:1 MUX between SATA Port 1 and the M.2 connector. The M.2 SATA bus is shared with SATA Port 1, therefore if you install an M.2 SATA SSD card, SATA Port 1 (J3) will automatically get disabled.
The power delivery of the HDDs is devided into two group:
* HDD Rail A (Max. 3x Drives)
* HDD Rail B (Max. 2x Drives)
Helios64 implements a power staggering approach where *HDD Rail A* will be powered up first, then few seconds later *HDD Rail B* will be powered up. This power control scenario is performed to reduce the inrush current during disk spin-up.
As part of Helios64 official enclosure, an HDD/SSD harness is provided to connected both SATA + Power signals between Helios64 board and the 5x HDD slots.