"Academics Find Critical Flaws in Self-Encrypting Hardware Drives"
https://threatpost.com/academics-find-critical-flaws-in-self-encrypting-hardware-drives/115103/
http://eprint.iacr.org/2015/1002.pdf
Basically if you bought & use the drives like any other external storage this shouldn't matter in the least. If OTOH you bought & use one to rely on the built-in encryption, Oops... time to rethink that & look at alternatives, including software like Veracrypt.