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MODFLOW-2000 has new packages and capabilities
- Incredibly FAST solver (LMG Package)
Table 1. Comparison of computational differences between the PCG2 and LMG solvers for several different ground-water flow problems. Unless otherwise indicated, DAMP=1.0 and ICG=0 for all simulations. [SS, steady-state; TR, transient; L, linear; NL, nonlinear; #, number; MB, megabyte]
| Problem | Type | # of Nodes(# of layers, # of rows,# of columns) | PCG2 | LMG | ||||
| CPU Time (seconds) | Memory(Mb) | # of Iterations | CPU Time (seconds) | Memory(Mb) | # of Cycles | |||
| 1 | SS NL | 1,728,000 (60, 240, 120) | 3,082 | 121 | 565 | 1,761 11,352 | 940 1966 | 40 124 |
| 2 | SS L | 1,050,000 (1, 1500, 700) | 5,243 | 50 | 2465 | 205 | 340 | 9 |
| 3 | TR NL | 147,440 (4, 190, 194) | 852 | 14 | 4328 | 631 | 72 | 175 |
| 4 | SS L | 465,600 (15, 194, 160) | 942 | 47 | 1864 | 50 | 151 | 9 |
| 5 | SS NL | 74,817 (3, 163, 153) | 654 | 8 | 3718 | 2108 354 459 | 229 329 429 | 246 325 427 |
2 DAMP=0.50
3 DAMP=-1 (Adaptive damping using Cooley’s method)
4 DAMP=-2 (Adaptive damping using the relative reduced residual method)
mchill@usgs.gov
Last Modified: September 12, 2012