The dual drive hdparm thing is one issue,
but I suppose we should set that aside
and concentrate on getting a single drive config going first.

So unplug one drive, and use just a single SSD for now.

Here's a special hijack image that waits longer for DRQ on writes.

The theory is that they're pre-erasing the sectors before
allowing the data transfer to begin, and this is taking a
while. Especially when our transfers are so tiny, requiring
lots of erasing and data shuffling internal to the SSD.