  In Lattice QCD, a major challenge in simulating physical quarks is the
computational complexity of these simulations. In this proceeding, we describe
the optimisation of Clover fermion action for Blue gene-Q architecture and how
different iterative solvers behave for Domain Wall Fermion action. We find that
the optimised Clover term achieved a maximum efficiency of 29.1% and 20.2% for
single and double precision respectively for iterative Conjugate Gradient
solver. For Domain Wall Fermion action (DWF) we found that Modified Conjugate
Residual(MCR) as the most efficient solver compared to CG and GCR. We have
developed a new multi-shift MCR algorithm that is 18.5% faster compared to
multi-shift CG for the evaluation of rational functions in RHMC.
