My only complaint is that using OpenMP Eigen can be slower with SMT than without SMT. They even suggest telling to use half as many threads as you have "cores" when "cores" means twice as many due to SMT.
Otherwise, we've seen a 8-10x performance increase in SolveSpace (CAD) in some situations after switching from home-grown matrix operations to Eigen.
Otherwise, we've seen a 8-10x performance increase in SolveSpace (CAD) in some situations after switching from home-grown matrix operations to Eigen.