The software-based encryption will be a bit slower but should be more secure. As Tom's Hardware points out, the reason for this change is because many SSDs with hardware-based encryption do not offer proper security:
"SwiftOnSecurity" called attention to this change on September 26. The pseudonymous Twitter user then reminded everyone of a November 2018 report that revealed security flaws, such as the use of master passwords set by manufacturers, of self-encrypting drives. That meant people who purchased SSDs that were supposed to help keep their data secure might as well have purchased a drive that didn't handle its own encryption instead.For existing drives, nothing will change.
Microsoft gives up on SSD manufacturers: Windows will no longer trust drives that say they can encrypt themselves, BitLocker will default to CPU-accelerated AES encryption instead. This is after an exposé on broad issues with firmware-powered encryption.https://t.co/6B357jzv46 pic.twitter.com/fP7F9BGzdD— SwiftOnSecurity (@SwiftOnSecurity) 27 september 2019