A Flexible Global GCRO-DR Method for Shifted Linear Systems and General Coupled Matrix Equations

Table 6

Performance comparisons for the general coupled Sylvester matrix equations.

Problems		Method
		GL-GCRO-DR	FGL-GCRO-DR	GL-GMRES ()	FGL-GMRES ()	GL-GMRES-DR	FGL-GMRES-DR
= 50	mvps	134	37	239	37	130	29
	T (s)	4.060e − 01	1.336e − 01	2.988e − 01	1.396e − 01	9.266e − 01	3.421e − 01
= 60	mvps	217	41		59	173	46
	T (s)	6.551e − 01	2.165e − 01		2.195e − 01	1.668e + 00	7.521e − 01
= 70	mvps	243	53		115	232	61
	T (s)	1.042e + 00	3.929e − 01		6.168e − 01	3.112e + 00	1.354e + 00
= 80	mvps	507	100		507	334	138
	T (s)	2.661e + 00	8.868e − 01		2.661e + 00	6.143e + 00	3.894e + 00
= 90	mvps	507	100			503	175
	T (s)	3.294e + 00	1.109e + 00			1.206e + 01	6.228e + 00
= 100	mvps		166				228
	T (s)		2.326e + 00				9.962e + 00