As Unity has confirmed on their forums, they're definitely working on supporting Metal. I'm a bit skeptical, though, existing games will benefit from this, unless they'll be upgraded to the version of Unity that'll support Metal. Seems like too many unknowns at this time even for Obsidian...
OSX El Capitan and Metal
in Pillars of Eternity: General Discussion (NO SPOILERS)
Posted
As Unity has confirmed on their forums, they're definitely working on supporting Metal. I'm a bit skeptical, though, existing games will benefit from this, unless they'll be upgraded to the version of Unity that'll support Metal. Seems like too many unknowns at this time even for Obsidian...