Hello guys,

I am trying to pick between the two (for now I am not familiar with any), however they both seem to be badass...

About my problem: I need to solve ~100 coupled advection equations in 3D with DG. Flux in advection is linear and constant, however all equations are nonlinearly coupled with source. I know what I need to do with Rimann problem - solve it at the begining exactly (essentially decompose 100x100 flux matrix, which is in itself block diagonal). I need AMR, good parallel scaling, and maybe in the future some non-trivial geometry.

Both packages seem to have what I need, however I never worked with any of them to know for sure.

Deal_ii seem to have better documentation. However, maybe I will be able to find someone around me familiar with MFEM, maybe.

MFEM seem to me more lightweight, hackable and easy to use, but deal_ii looks more mature.

Performance wise they seem to be comparable.

They both are linked to something which may be important, i.e., petsc, hyper...

In the future, I may want to solve this system in time not only explicitly, but also implicitly or with IMEX

Any input or advice is appreciated,

Thank you!