I used to enable OpenMP that would multithreaded composite actions. But I wanted to get rid of the Visual Studio C++ Redistributable and to do that I had to drop support for OpenMP. Due to that change Magick.NET will perform much better in Parallel mode. But that means it will now only use one of your cores.
I don't know all the details of your Composite actions but you might be able to split your actions up in areas. For example when you have an 100x400 you split this up in 4 threads that composite 100x100. Important here is that you use the whole width of your image to get better memory reads. Not sure if that would work in your situation though but you could give it a try.
I don't know all the details of your Composite actions but you might be able to split your actions up in areas. For example when you have an 100x400 you split this up in 4 threads that composite 100x100. Important here is that you use the whole width of your image to get better memory reads. Not sure if that would work in your situation though but you could give it a try.