I'm sure it's hard to do a detailed eye analysis at those speeds. But come on, I can get a hub that does 10Gbps per lane (so 20Gbps equivalent) for $13, 40Gbps SSD enclosures for $40, and 80Gbps SSD enclosures for $150. Making that signal do a loop, maybe adding some artificial attenuation, and checking how many bits get corrupted shouldn't need fancier hardware than that.
I'm sure it's hard to do a detailed eye analysis at those speeds. But come on, I can get a hub that does 10Gbps per lane (so 20Gbps equivalent) for $13, 40Gbps SSD enclosures for $40, and 80Gbps SSD enclosures for $150. Making that signal do a loop, maybe adding some artificial attenuation, and checking how many bits get corrupted shouldn't need fancier hardware than that.