On the face of it, when any SuperHub is in modem mode it should not effect the throughput and so I posted http://community.virginmedia.com/t5/Speed/Vivid-200-Gamer-connections/td-p/3302651 thinking that was so, However....
I asked to revert to 152/12 whilst keeping the SH3 in use and the problem of not being able to open more than about 500 concurrent TCP connections before pages load times hit about a minute persisted.
It was really only the 20 up part of the Vivid 200 Gamer package that I wanted but, using it in the way I do it just will not perform
So, this led to the further reversion to 152/12 with SH1. Now everything works again, albeit at the slower speed.
VM tell me that 200/20 will not run on SH1
My use is not few connections with GB size files rather x,000 connections with ~30 KB files
I am open then to ideas pertaining to why this might be