Quick question... Does Fast Healing stack from seperate sources?

Just curious if Fast Healing stacks? I have it from two different sources. One from an inherent/personal source (part of the race), and one from the Dragon Shaman Vigor Aura (which only kicks in at less than half hit points).

So assuming I get knocked down to below half HPs, would I get healed 1 point from each source?

It doesn't stack.

If it's fast healing 1 from two different sources, you still only gain 1 hp per round. Because one is from race, that will always apply.

If the fast healing came from sources other than race, there could be circumstances where one fast healing would kick in over the other (especially if one fast healing source heals more than another).