Solver Error in EM-LF Simulation on Yoon-son Model

[viniltc]

Hi all,

I'm running a low-frequency neurostimulation simulation on Sim4Life Web using the Electro Ohmic Quasi-Static solver on the Yoon-son complete anatomical model.

Simulation settings:

Frequency: 1000 Hz
Electrodes: Two placed on the chest area

Boundary Conditions:
Flux boundary automatically applied to external bounding planes
Dirichlet boundary applied to both electrodes (set as “Treated as Port”)

The simulation took approx. 45 minutes to solve, but I encountered an error at the end. Here are the last lines of the log:

2025-05-30T11:23:35.790Z [INFO] [XCore.CLog] Iteration 4 and residual drop factor 5.33458e-06
2025-05-30T11:23:35.791Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":430,"type":"0","version":"0"}}}
2025-05-30T11:24:04.150Z [INFO] [XCore.CLog] Iteration 5 and residual drop factor 8.98461e-07
2025-05-30T11:24:04.152Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":500,"type":"0","version":"0"}}}
2025-05-30T11:24:32.557Z [INFO] [XCore.CLog] Iteration 6 and residual drop factor 4.14111e-07
2025-05-30T11:24:32.558Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":530,"type":"0","version":"0"}}}
2025-05-30T11:25:00.816Z [INFO] [XCore.CLog] Iteration 7 and residual drop factor 4.9417e-08
2025-05-30T11:25:00.818Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":600,"type":"0","version":"0"}}}
2025-05-30T11:25:29.127Z [INFO] [XCore.CLog] Iteration 8 and residual drop factor 1.48857e-08
2025-05-30T11:25:29.128Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":650,"type":"0","version":"0"}}}
2025-05-30T11:25:57.655Z [INFO] [XCore.CLog] Iteration 9 and residual drop factor 2.25318e-09
2025-05-30T11:25:57.657Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":720,"type":"0","version":"0"}}}
2025-05-30T11:26:25.941Z [INFO] [XCore.CLog] Iteration 10 and residual drop factor 2.95529e-10
2025-05-30T11:26:25.942Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":790,"type":"0","version":"0"}}}
2025-05-30T11:26:54.268Z [INFO] [XCore.CLog] Iteration 11 and residual drop factor 6.34014e-11
2025-05-30T11:26:54.270Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":840,"type":"0","version":"0"}}}
2025-05-30T11:27:22.560Z [INFO] [XCore.CLog] Iteration 12 and residual drop factor 1.48467e-11
2025-05-30T11:27:22.562Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":900,"type":"0","version":"0"}}}
2025-05-30T11:27:50.924Z [INFO] [XCore.CLog] Iteration 13 and residual drop factor 1.8532e-12
2025-05-30T11:27:50.926Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":970,"type":"0","version":"0"}}}
2025-05-30T11:28:19.032Z [INFO] [XCore.CLog] Iteration 14 and residual drop factor 3.03701e-13
2025-05-30T11:28:19.035Z [INFO] [XCore.CLog] JSON PROGRESS : [Info]  {{{"descriptor":"Solving linear system: Real Part","permill_completed":1000,"type":"0","version":"0"}}}
2025-05-30T11:28:19.037Z [INFO] [XCore.CLog] Elapsed time for 'Solving linear system: Real Part' was 00:07:06 wall clock time.
2025-05-30T11:28:19.039Z [INFO] [XCore.CLog] Solved linear system: Current and peak CPU memory usage:  42.5 GB /  42.5 GB (current is 100.0 % of peak)
2025-05-30T11:28:19.041Z [INFO] [XCore.CLog] Solver returns: 'converged (relative tolerance)'.
2025-05-30T11:28:21.522Z [ERROR] [XCore.CLog]  
2025-05-30T11:28:21.524Z [ERROR] [XCore.CLog] The solver process failed to exit correctly: eExitFail

The solver fails to exit cleanly. During the run, I observed CPU memory usage jumping from about 40% to 100% at times. Could this indicate that memory limitations caused the eExitFail error?

Has anyone seen a similar issue with large anatomical models? Any suggestions on how to debug or avoid this error?

Thanks in advance