Belatedly, I discovered my brand new Dell laptop installed the OS to the 1TB hybrid, and left the 256GB SSD as my "spare".
The sum total of all the partitions on the 1TB are well below 256GB, but my attempts to restore and/or disk-copy to the SSD are failing.
And, whether it's because it's Windows 8.1 or not, there are a lot more 'required' partitions than there ever used to be

See attached for the partitions list, sizes and/or descriptions.