Do I need a better PC?

Im finding it quite hard to track down a mini itx or micro atx mobo with intel NIC. they all like to use the realtek it seems.

Maybe i should just get an add on card with intel chips?

It's possible that the noise is due to the servos getting a bad rotor "home"
This only applies to brushless motors, but the drives need to know where the rotor magnets are relative to the motor windings.
If you are using EtherCAT then this is probably all inside the drives, so I am not sure how you could ever be sure if this is the problem. Do you know how the drives perform this step? (If they use absolute encoders or hall sensors then this is unlikely to be the problem)

They have single turn absolute encoder.
I don't think its a motor issue because all of them do it exactly the same, or they are all fine someimes. I put together a better b450 motherboard with a ryzen 3200g. Seems better than the $0.50 HP motherboard already. I think it does have realtek chip so I have an Intel card to stick in it too.

I've been messing with this again. I have an intel 2 ports pcie lan card that I tried to use. I got the ip address from ip a command and put it in the etc/ethercat.config. for some reason only the lan on the motherboard works even with the address changed. But the servos were crunchy sounding and it was disconnecting randomly. I put it back to the correct address for the motherboard port and its smooth. I have not been able to run ethercats on the pci card.

In other news, my new pc build runs much better generally and I don't have the real-time delay error warnings anymore. And I've been busy making mechanical progress on my machine.  

youtube.com/shorts/gAclUIYUk1Y?si=PEWtBkNokJtn4JyQ