My friend has built a device with these wires, and the PCIe risers she had, were found to have PEWAKE and PERST, and the design has worked wonders. However, later on, a riser compatibility ...

Throughput is good, too, reportedly sitting at roughly 60-70 MB/s. The hard part is probably finding a PCI-X riser; PCI-Express stuff is far more common. Few of us need to deal with PCI-X anymore ...