I bought a 9400-16i, but it hasn't arrived yet (US-UK).
The 9400-16i 'Product Brief' describes the board as being capable of 8 no. direct attached NVMe drives at PCIe x2 and the controller is capable of supporting 24 no. NVMe drives.
In the meantime, I have been in discussion with Broadcom and they explained that at the moment, 4 no. NVMe is the maximum this board can accommodate, as there are no cables allowing 8 no. NVMe drives from the 4 no. Mini SAS HD ports, the feature of '8 no. x2 NVMe' is currently disabled on the controller, there are no PCIe x2 NVME drives on the market and there are no NVMe expander switches on the market.
Theres not much I can do about '8 no. x2 NVMe' being disabled in the firmware.
Would such a custom cable require bifurcation such as x4>x2x2?
I understand any PCIe device correctly designed to PCIe standards can operate on fewer lanes, just at slower speeds. NVMe PCIe x4 SSD drives can also work at x2 and therefore PCIe x2 designed NVMe is not required.
Do NVMe expander switches exist on the market?
The 9400-16i 'Product Brief' describes the board as being capable of 8 no. direct attached NVMe drives at PCIe x2 and the controller is capable of supporting 24 no. NVMe drives.
In the meantime, I have been in discussion with Broadcom and they explained that at the moment, 4 no. NVMe is the maximum this board can accommodate, as there are no cables allowing 8 no. NVMe drives from the 4 no. Mini SAS HD ports, the feature of '8 no. x2 NVMe' is currently disabled on the controller, there are no PCIe x2 NVME drives on the market and there are no NVMe expander switches on the market.
Theres not much I can do about '8 no. x2 NVMe' being disabled in the firmware.
Would such a custom cable require bifurcation such as x4>x2x2?
I understand any PCIe device correctly designed to PCIe standards can operate on fewer lanes, just at slower speeds. NVMe PCIe x4 SSD drives can also work at x2 and therefore PCIe x2 designed NVMe is not required.
Do NVMe expander switches exist on the market?