Amarra Plus can do both kinds of DSD transmission -- native or DoP. The latter should use effectively no processing, as it is just a PCM-like container with the DSD data inside, necessary for passing it through equipment that needs to see PCM packet headers and the like. If you're seeing a lot of CPU in something like the Roon player, then it is due to re-sampling as someone pointed out. I'm borrowing a DAVE next month. I'll try it with DSD and see how things go.