Re: NEC-LIST: Memory constraints in NEC2

Yes, when NEC runs out of RAM, it uses disk arrays. You can recompile NEC2
for larger problems, using these modifications below, as reported by Chuck
Counselman (ccc_at_space.mit.edu). Your problems can then be larger and run
faster (due to no swapping.)

____________________ Chuck's work below ------------------------------
The accompanying Stuffit compressed files named NEC2.600.sit,
NEC2.3600.sit, and NEC2.4800.sit expand into Power-Macintosh-native
applications named NEC2.600, NEC2.3600, and NEC2.4800, respectively. These
applications were compiled and linked with the Absoft FORTRAN 77 Software
Development Kit v. 4.2 for the Power Macintosh, from the NEC-2 FORTRAN
source file included in <http://www.io.com/~knalty/NEC2.PPC.sit.HQX> as of
August 1996.

NEC2.600 requires 2055 K of RAM (if VM is on) and handles up to 600 wire
segments in four symmetry cells of 150, e.g., 150 seg's in the first
quadrant, with two planes of symmetry.

NEC2.3600 requires 26664 K of RAM (if VM is on) and handles up to 3600 wire
segments in four symmetry cells of 900, e.g., 900 seg's in the first
quadrant, with two planes of symmetry.

NEC2.4800 requires 46578 K of RAM (if VM is on) and handles up to 4800 wire
segments in four symmetry cells of 1200, e.g., 1200 seg's in the first
quadrant, with two planes of symmetry.

To make NEC2.3600, for example, I modified the source code to change LD and
NM to 3600, N2M to 7200, N3M to 10800; and IRESRV and the dimension of
array CM to 900*3600 = 3240000.

- Chuck Counselman <ccc_at_space.mit.edu> October 3, 1996

knalty_at_io.com knalty_at_AOL.com
Received on Wed Feb 12 1997 - 09:08:24 EST