summary: I have an ASUS PRIME x399-a motherboard, and the PCIe slot placements are nonsensical. this results in some slots being unusable simply by being too close together. im looking for a product to effectively relocate a PCIe x16 connector.
Specifics:
here is the PCIe layout from my boards manual.
I have double-wide PCIe devices in slots 1 and 3 (GPUs), a single-wide device in slot 6 (10Gbe NIC). due to irrelevant details of my setup, these devices absolutely cannot be moved to different slots (chipset vs direct-to-cpu nonsense) .
the double-wide device in slot 1 obstructs slot 2, and the double-wide device in slot 3 obstructs slot 4.
i wish to add another (single-wide, but half-height) PCIe device to my setup here. but it seems my only available slot is the x1 connection on slot 5. PCIe x1 performance would be unacceptable here.
if slots 4 and 5 were in swapped positions, all my problems would be solved. is there any riser/bridge/adapter i can buy that is small enough to connect to slot 4, fit within the almost-zero clearance underneath the GPU in slot 3, and have the x16 connector at half-height (or lower, i can mess around with the bracket) right above slot 5?
this motherboard has 4 PCIe x16 connectors, it would be really cool if i could use all of them.
I am open to external solutions, as long as performance is maintained (none of that USB stuff). I have plenty of space on my rack.