Idea: Multi-purpose PCIe riser card

[maxtch]

This comes from my previous post: 

 

 

The idea is to create a multi-purpose PCIe riser card that combines a few common low-bandwidth interfaces into one PCIe card, intended for the people who is forced to hold off upgrading their motherboards, cannot upgrade, or flat out ran out of PCIe slots.

 

Variant 1: PCIe x1 to 2x mPCIe + 2x USB 2.0

This is the simplest variant, based on Diodes Incorporated PI7C9X442SL PCIe x1 to dual x1 switch + USB 2.0 EHCI bridge chip.

This card occupies one PCIe x1 slot, and provides two mPCIe slots each with PCIe x1 and USB 2.0 signals, and a dual USB 2.0 internal header. One of the two mPCIe slots also have the support of a SIM card.

 

Variant 2: PCIe x4 to mPCIe + 4x USB 3.0

This is based on the Diodes Incorporated PI7C9X2G304EL PCIe 2.0 x2 to dual x1 switch, ASMedia ASM1142 USB 3.0 XHCI chip, and a USB 3.0 hub chip. Admittedly the XHCI chip is being bottlenecked but it should not be that big of a problem, since only one of its two ports can operate up to 5Gbps speeds.

This card occupies one PCIe x4 slot, and provides a mPCIe slots each with PCIe 2.0 x1 and USB 2.0 signals and two dual USB 3.0 internal header. The mPCIe slot also have the support of a SIM card.

 

Variant 3: PCIe x4 to M.2 + mPCIe + 4x USB 3.0 + 1x SATA 6Gb/s

This is the most complicated variant, based on Diodes Incorporated PI7C9X2G612GP PCIe 2.0 x4 to x4 + quad x1 switch, ASMedia ASM1061 PCIe dual port SATA AHCI chip, ASMedia ASM1142 USB 3.0 XHCI chip, a USB hub chip and maybe an PCIe Option ROM chip. Admittedly the XHCI chip is being bottlenecked like above but it should not be that big of a problem, since only one of its two ports can operate up to 5Gbps speeds. The M.2 is also choked to PCIe 2.0 speeds, but I am not sure how saturated it is under modern NVMe drives. The Option ROM chip holds the necessary BIOS and UEFI Option ROM code to allow older motherboards to boot from the NVMe drive without native BIOS support.

This card occupies one PCIe x4 slot, and provides one M.2 slot capable of running in both SATA 6Gb/s and PCIe 2.0 x4 mode, a mPCIe slots each with PCIe 2.0 x1 and USB 2.0 signals, a SATA 6Gb/s slot and two dual USB 3.0 internal header.