IMO, whether Ethernet cable a factor is function to DAC buffer size. Bigger the buffer, less factor.
Less a factor for what?
Problem is most DACs buffer's ~6 seconds and I can easily hear a difference between Ethernet cables. If you in my neck of woods, I would love to demonstrate in my system.
I can set JRiver for 6 seconds. So an Ethernet cable will effect that 6 second buffer but if I set JRiver for 60 minutes of buffer it won't?
What about all the other operations going on? CPU caching operations, Interrupts, DMA transfers, Memory Paging, SMPS? This is why I don't buy into Al's argument.
With all this going on what ever variation of cable is going to be swamped by the system wide operations going on continuously.
What is your neck of the woods and what is your setup?