Choosing the Ensemble: EnsembleGPUArray vs EnsembleGPUKernel

The short answer for how to choose an ensemble method is that, if EnsembleGPUKernel works on your problem, you should use it. A more complex discussion is the following:

• EnsembleGPUKernel is more asynchronous and has lower kernel call counts than EnsembleGPUArray. This should amount to lower overhead in any case where the algorithms are the same.
• EnsembleGPUKernel is restrictive on the types of ODE solvers that have been implemented for it. If the most efficient method is not in the list of GPU kernel methods, it may be more efficient to use EnsembleGPUArray with the better method.
• EnsembleGPUKernel requires equations to be written in out-of-place form, along with a few other restrictions, and thus in some cases can be less automatic than EnsembleGPUArray depending on how the code was originally written.