When you test a harddrive system with the Decklink or AJA system test. it give you MB/s
When you do a Read/Write test with a Decklink or AJA system test it’s gives you MegaBytes/s
A 100 Mb/s video codec will need 12.5 MB/s datarate for one stream.
When you say my SATA raid does 300 Mb/s, you probably mean 300 MB/s.