PCIe switch vs PCIe mux and Demux

Question

In my project my customers wanted a 2 port 2 lane PCIe switch and The switch is occupying more space than I can allocate on the board, Before I can ask my customers to get approval on using an integrated PCIe MUX and DEMUX (https://datasheets.maximintegrated.com/en/ds/MAX4969.pdf) in the board for the both ports, I want to know what are major differences between both.

Because as far as I know, Since PCIe is a point to point communication unlike ethernet where any device can communicate with any device. By providing PCIe mux and demux, it is equivalent to providing a dedicated PCIe link when select bit is used for A or B.

Kindly answer What would be the major challenges in using PCIe MUX/DEMUX over a packet switch ?

Thank you,

Jay

Answer 1

A switch routes and buffers the packets so that both devices can be active at the same time.

A mux/demux allows only one device to be active at the same time. The other device is disconnected, as if it were unplugged. (Please note that not all PCIe hosts or devices support hotplugging.)