This applies to the Saffire Range
The Saffire range will work with Thunderbolt 1/2 (DisplayPort) and Thunderbolt 3 (Type-C) ports.
In order to set this up on a system with a Thunderbolt 1/2 port, you will need a Thunderbolt to Firewire adapter and a Firewire 800 to 400 cable.
The performance will not change when using these adaptors.
If you cannot see the Saffire in Saffire Mix Control on macOS 10.13+ please see the following article: