1Running cg with none preconditioning 2 0 KSP Residual norm 1.41421 3 1 KSP Residual norm 0.707107 4 2 KSP Residual norm 0.471405 5 3 KSP Residual norm 0.353553 6 4 KSP Residual norm 0.282843 7 5 KSP Residual norm < 1.e-11 8