Since there are adapters to adapt M.2 to PCIe x4, I was wondering if such an adapter can be used to connect other PCIe devices like network interfaces or USB controllers to the system?
Are there any special features that need to be supported by the motherboard for this to work (besides having a M.2 connector that is hooked up to PCIe of course).
An M.2 slot basically has 4x PCIe V3.0 and a regular SATA port in 1 connector.
Those adapters break out the PCIe lanes and feed them into a normal PCIe 4x connector which should be able to take any PCIe 1x and 4x card (provided you can physically fit that somehow it in your PC case).
Whether it will actually work properly??? Maybe...
The PCIe lanes are a very high-speed bus. Adding more wiring length (which this converter does) to that might cause problems with electrical interference.
Some PCI-e cards may be fine with it. Others may not. Trail and error is the only way to say for sure.
If I were to guess: The faster the PCIe device put in such a converter the more potential for trouble.
A PCIe 1x serial adapter is probably fine. A 10 Gb/s network card probably not.
