Parallel Multiprojection Preconditioned Methods Based on Subspace Compression

Table 1

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

Poisson 3D	Cores/subdomains
	64	128	256	512	1024
MPMSC
Pre-Time	367.38	70.04	21.45	6.31	3.64
Comm-Time	23.54	13.63	10.92	9.81	8.39
GMRES-Time	122.45	73.77	56.45	50.85	41.51
Total-Time	489.84	143.81	77.90	57.16	45.14
Iterations	4 ()	4 ()	4 ()	4 ()	3 ()
Aggregates	13	20	40	84	162
Preconditioned Relative Residual
Relative Residual