Testing 2.5 Gbps Ethernet on the Raspberry Pi CM4
I got this Rosewill RC-20001 PCIe 2.5 Gbps Network Adapter working on the Raspberry Pi Compute Module 4.
Right after I got the card working, though, I tested it in an external powered PCI Express riser, and that test released the card's magic smoke. Oops.
Here's a dramatic re-enactment that's actually pretty accurate to what it looked like in real life:
Luckily, buying a replacment wasn't too bad, since the card is less than $20. But to get it to work on my spiffy new ten gigabit network, I also had to buy a new SFP+ transceiver that was compatible with 1, 2.5, 5, and 10 Gbps data rates, and that cost $60!