Stuff has arrived and looks exactly as advertised. Still waiting for ram and cpu so i have not yet had a poke at it. Shinreal has been quick to respond and sent me the following information for configuring:
- Download and install the PCI/PCIe SDK Windows Complete Package (other OS support is available - its java)
- Start plxmon and click the EEPROM button in the toolbar
- Load one of the included files or update manually and click “write”
- Restart pc
Seems like the software allows for saving premade configs, so there’s probably a way to make this all cli friendly.
This is untested by me and there are still a few things i don’t understand. As for manual config:
Register 300h Port Configuration
The port bandwidth configuration is valid only Port 0
| Bit(s) | Description | Serial EEPROM andI2C |
|---|---|---|
| 2:0 | Port Configuration for Station 0 Port Configuration Link width, per Port, for Station 0. 000b = 0 = Reserved 001b = 1 = x16 010b = 2 = x8x8 011b = 3 = x8x4x4 100b = 4 = x4x4x4x4 101b = 5 = x8x2x2x2x2 110b = 6 = x4x4x2x2x2x2 111b = 7 = Reserved |
Yes |
| 5:3 | Port Configuration for Station 1 Port Configuration Link width, per Port, for Station 1. 000b = 0 = Reserved 001b = 1 = x16 010b = 2 = x8x8 011b = 3 = x8x4x4 100b = 4 = x4x4x4x4 101b = 5 = x8x2x2x2x2 110b = 6 = x4x4x2x2x2x2 111b = 7 = Reserved |
Yes |
| 8:6 | Port Configuration for Station 2 Port Configuration Link width, per Port, for Station 2. 000b = 0 = Reserved 001b = 1 = x16 010b = 2 = x8x8 011b = 3 = x8x4x4 100b = 4 = x4x4x4x4 101b = 5 = x8x2x2x2x2 110b = 6 = x4x4x2x2x2x2 111b = 7 = Reserved |
Yes |
| 31:9 | Reserved |
Need to figure out if this is applicable to just this Shinreal card or all PEX 8749 cards, including silicon revisions. And what “Station” is.
Will be fun to mess with once the rest of the hardware arrives 
Meanwhile, the PEX 8749 product brief is an interesting read. I havn’t really seen any direct pcie machine ↔ machine stuff in the wild.