@feld HDD's tend to be smart for surveillance video.

Surveillance video is write heavy and requires lots of space, but is at a fixed rate, so all you need is a HDD that can keep up with the write requirement and you're golden and you will have video footage for many hours before a overwrite and HDD's are also pretty cheap for lots of storage.

SDD's for surveillance video would be dumb, as SDD's have a pretty bad lifespan under constant writes, SSD controllers are also know to misbehave under sustained writes and SSD's are very expensive when it comes to large amounts of storage.