You understand that everything I said was... Plug in the right values here: https://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-pc

You understand that everything I said was... Plug in the right values here: https://www.digikey.com/en/resources/conversion-calculators/conversion-calculator-pcb-trace-impedance https://www.digikey.com/en/resources/conversion-calculators/... You don't need an EE degree to look at your PCB-manufacturer's specifications. Lets run a brief example: https://www.digikey.com/-/media/Images/Marketing/Resources/DKRed/DKRed%20-%204%20Layer%20Stack%20Info.pdf?la=en-US&ts=8f209b2c-515f-495d-a3da-806b275c331d https://www.digikey.com/-/media/Images/Marketing/Resources/D... Lets go for Edge Coupled Microstrip. Solve for Trace Width. I believe Ethernet is 100 Ohms differential impedance. Set the top to 100. Trace Thickness as per DKRed is 0.5 oz/ft^2. This value might be 1 on different manufacturers. Height is 7.04 mil. Just steal it from the specsheet above. Spacing is whatever you plan to do. Lets say 8-mil. Dielectric Constant is 4.01: https://www.digikey.com/-/media/Images/Marketing/Resources/DKRed/185hr%20Datasheet.pdf?la=en-US&ts=fdcadd73-9742-4bb2-b3d8-e693d8bddd48 https://www.digikey.com/-/media/Images/Marketing/Resources/D.... See "Dk", Dielectric Constant. ------------------ Bam. Now 9.814 mil thickness for differential pair Ethernet routes. Yeah, it will take you some study. But I literally laid everything out in front of you with my post above. It shouldn't take you any more than like 30 minutes of studying at this point now that I put everything in just a few posts for you. An EE Degree will help. But... there's not much to this particular issue. You need to understand that different manufacturers have different thicknesses, dielectric-constants and other such measurements. But its all plug-and-play once you know how to read a spec-sheet. -------- If that's too hard, just don't route Ethernet or USB I guess? There aren't very many differential-pair lines or impedance-matched lines on the Rasp. Pi4 CM as far as I can tell.