[woodchuck64]

> ‘the biological brain cannot support multiple separate conscious attentional processes in the same brain medium’.

And that is probably because consciousness just is awareness of attention, as Graziano suggests: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3223025/

So if so, we should be able to run conscious awareness on a much faster silicon substrate (technology permitting) having it sequentially processing (becoming aware of) the memories of conscious experience of many biological brains absorbed in parallel. The hive mind then is just thinking and experiencing faster.