I/O is already meeting those performance levels on today's technology.
You can get a hundred dollar SSD that has a read speed around 7 gigabytes per second using just over five watts. That will fill up 8x80GB in a minute and a half of load time. If your energy budget is 24 watts then install four and make it 20-25 seconds.
As far as cost, I don't know what the proposed chip would be, but $400 is 0.5% of that pile of GPUs and SSDs will only get cheaper.
You can get a hundred dollar SSD that has a read speed around 7 gigabytes per second using just over five watts. That will fill up 8x80GB in a minute and a half of load time. If your energy budget is 24 watts then install four and make it 20-25 seconds.
As far as cost, I don't know what the proposed chip would be, but $400 is 0.5% of that pile of GPUs and SSDs will only get cheaper.