. Author manuscript; available in PMC: 2022 Aug 19.

Published in final edited form as: J Neural Eng. 2021 Aug 19;18(4):10.1088/1741-2552/ac17d7. doi: 10.1088/1741-2552/ac17d7

Table 3.

Comparative performance of two modeling methods for a realistic (isotropic) head model. The FEM run times are for Intel Xeon E5–2698 v4 CPU (2.20 GHz) workstation with 256 Gbytes of RAM. The BEM-FMM run times are given for Intel Xeon E5–2683 v4 CPU (2.1 GHz) based workstation. The relative error in the field magnitude (based on 2 norm) is given for intracranial tissues (CSF, gray/white matter) only.

Ansys FEM	Ansys sol. time (8 cores)	BEM-FMM sol. Time	Intracranial rel. field magn. error for an arc in Fig. 4c	Intracranial rel. field magn. error in the entire coronal plane
4.8 M tets, 3 adapt. passes	2 h 29 m	~60 sec (rel. residual of 10⁻³)	3.1%	6.31%
6.9 M tets, 4 adapt. passes	6 h 23 m		3.0%	6.15%
9.0 M tets, 5 adapt. passes	8 h 43 m		2.9%	6.06%