[dbuder]

No, there was a DIY diode prob with a headline number high enough, but I think he said real world performance would be about 8ghz, that's only part of the problem anyway. I had a look, I can't find the forum post or the podcast he was on (amphour). Either rent an appropriate USB analyzer or scope. If you just want to verify the speed of your consumer equipment look for a software solution to measure throughput (there is significant protocol overhead). At the required speed you can't even use BNCs.