Are there any other options?

You could also pass ownership of the your single GPU queue from thread to thread, so that the thread processing the first range of your list performs it's own submission, then the thread that owns the 2nd range performs it's submission, etc... IMHO that would be much more complex and require more synch work than just having N write-command-list jobs, followed by a single submit job with a dependency between them. The latter should easily fit into any modern engine's job system.

IMHO that would be much more complex and require more synch work than just having N write-command-list jobs, followed by a single submit job with a dependency between them.

http://www.gamedev.net/topic/673336-dx12-m-commandallocator-reset-is-necessary-every-frame/

In this thread Sergio J. de los Santos seems convinced that in D3D12 commandlist building is cheap but submission is expensive. I haven't confirmed this yet but if true wouldn't overloading one thread with submission be suboptimal?

In this thread Sergio J. de los Santos seems convinced that in D3D12 commandlist building is cheap but submission is expensive. I haven't confirmed this yet but if true wouldn't overloading one thread with submission be suboptimal?

Putting commands into a cmd list is cheap, but you do it tens of thousands of times per frame. Submission is "expensive" for a single function call (similar to typical function calls in older D3D versions ) but you do it a handful of times per frame.

But will submitting all cmdlists through a single processor/thread reduce the number of draw calls from there maximums? Just curious.

Submitting the command lists is the quick bit, you can even submit multiple command lists in a single call to ExecuteCommandLists. It's unlikely to have any material effect on how many draw calls you can make per second.