Parallel Multiprojection Preconditioned Methods Based on Subspace Compression

Table 3

Convergence behavior and parallel performance of the PPGMRES() method, in conjunction with the MPMSC scheme with distance two neighborhood for the 3D Poisson problem ().

Poisson 3D	Cores/subdomains
	64	128	256	512	1024
MPMSC
Pre-Time	368.53	69.43	21.42	6.26	3.58
Comm-Time	24.14	16.63	12.21	11.72	12.62
GMRES-Time	133.28	90.17	66.13	64.25	61.81
Total-Time	501.81	159.60	87.55	70.51	65.39
Iterations	4 ()	5 ()	5 ()	5 ()	5 ()
Aggregates	6	9	19	32	51
Preconditioned Relative Residual
Relative Residual