  Lattice QCD simulations directly at physical masses of dynamical light,
strange and charm quarks are highly desirable especially to remove systematic
errors due to chiral extrapolations. However such simulations are still
challenging. We discuss the adaption of efficient algorithms, like multi-grid
methods or higher order integrators, within the molecular dynamic steps of the
Hybrid Monte Carlo algorithm, that are enabling simulations of a new set of
gauge ensembles by the Extended Twisted Mass collaboration (ETMC). We present
the status of the on-going ETMC simulation effort that aims to enabling studies
of finite size and discretization effects. We work within the twisted mass
discretization which is free of odd-discretization effects at maximal twist and
present our tuning procedure.
