using cables for high speed links (~6GB/s) is hard, and whilst there are a few problems that do not require much host/device communication, there are a signific

using cables for high speed links (~6GB/s) is hard, and whilst there are a few problems that do not require much host/device communication, there are a significant number that do - any increase in latency/decrease in bandwidth will be very noticeable in codes that otherwise perform well on accelerators (GPUs, etc.).