Ethernet Cables, do they make a difference?

Would you care to list the components involved with these 3 boutique testing?

1: Netgear ReadyNAS <> Cisco SG 200-8<> Cary DMS-500
2: Netgear ReadyNAS <> Cisco SG 200-8<> Cambridge 851N
3: Netgear ReadyNAS <> Cisco SG 200-8<> DIY ASRock 5300 Kabini based motherboard, 8GB Kingston DDR3, 120GB Kingston SSD, Windows 8.1 Pro, JRiver Media Center 22, WASAPI Exclusive Mode, Intel Pro 1000/Pt dual port.

Ports 7/8 on the SG 200-8 configured in a active dynamic LACP LAG and on the client computer the Intel NIC in a passive dynamic LACP LAG. This allows for removal of the cabling without interruption of layer 2 CAM table. Either cable can be swapped in real time while the music is playing from the back of the client computer.

18 inch Belkin Gold USB cable to Emotiva Stealth DC-1 balanced out to either a RME Fireface UFX and AKG 701’s for realtime monitoring or Yamaha P2500S to Curt Cambell Statements.

But all that doesn’t matter because if you are claiming your N.A. Ford Focus runs an 11 second 1/4 mile it really doesn’t matter what car I own. We aren't testing my claim, we are testing yours.

If it makes you feel better and you have money to burn go for it.
But this is something I know about intimately.
If ANY data cable passes data without packet loss, it cannot be improved upon.
Period.

1. Spend reasonable money.
2. Upgrade component.
3. Feel positive difference, and feel good about it.
4. Repeat...

Isnt that the goal?

In theory Ethernet cable does not make any difference for audio system but...

p.s. Teory is applicable in highly controlled environment which cannot be applied to every setup (or may be even majority of the setups).
p.p.s. Theories or rules have exceptions, which just prove the rules.

That is not the point. Ethernet cable can impact in two ways:  (1) reducing EMI interference; and (2) the connections. If it was impossible, period, the good Ethernet cables, from Cardas, Wireworld and Audioquest, would not improve the sound quality.  They do.  Period. You may not believe speaker cables and interconnects improve the sound quality, but the do. Period.

@jinjuku

IMO, whether Ethernet cable a factor is function to DAC buffer size.  Bigger the buffer, less factor.  Ideally DAC buffers the whole album, then anything before the DAC is not a factor ... play back from memory.     Companies probably making too much money selling transports, servers ... so not changing soon.

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.