| Science/Configuration Option | CAMx v6.10 | CMAQ v5.0.2 | Details |
| Nesting | One-way, Two-way, and Flexi-nest | One-way | |
| Horizontal Boundary Conditions | | | |
| Top Boundary Conditions | | No-mass exchange | |
| Meteorology | WRF-CAMx (Off-line) | MCIP (Offline); WRF-CMAQ (On-line) | |
| Emissions | 2-D with SMOKE (Off-line); In-line plume rise | 2-D with SMOKE (Off-line); In-line plume rise; Other in-line options: lightning, windblown dust, biogenics, sea salt | |
| Plume-in grid | GREASD (simple chemistry); IRON (complex chemistry) | None | |
| Gas-Phase Chemistry | CB05, CB6, CB6r2, CB6 with iodine; Mechanism 10 (user defined); SAPRC99 | CB05 with active chlorine chemistry, CB05 with updated toluene mechanism, CB05 with air toxics; SAPRC99, SAPRC07 with updated toluene chemistry | |
| Gas-Phase Chemistry Solver | EBI, IEH, LSODE/Gear | Rosenbrock, EBI, SMV Gear | |
| Photolysis | TUV | In-line | |
| Aqueous Chemistry | RADM-AQ | RADM | |
| Aerosol Chemistry | Two-mode course/fine scheme (modal) and multi-sectional CMU scheme (sectional) | AE5 (modal), AE6 (modal) with speciated crustal and other fine PM | |
| Aerosol Thermodynamics | ISOROPEA | ISOROPEAv2 | |
| Secondary Organic Aerosols | SOAP | CMAQ | |
| Other Chemistry | Multi-phase Hg; Surface Chemistry/Re-emission Model | Bi-directional Hg and NH3; Air toxics | |
| Dry Deposition | 11 category LULC (Wesely/Slinn), 26 category LULC (Zhang) | Wesely; MOSAIC (land-use dependent deposition velocities) | |
| Wet Deposition | Scavenging model | | |
| Horizontal Advection | PPM, Bott | PPM, PPM-Yamo | |
| Horizontal Diffusion | K-theory 1st order closure | Single eddy algorithm based on local wind deformation | |
| Vertical Advection | Implicit backward-Euler (time) hybrid centered/upstream (space) solver | PPM | |
| Vertical Diffusion | K-theory, ACM2 | ACM2 | |
| Integration Time Step | | | |
| Multi-Processing | OpenMP; MPI; Hybrid OpenMP-MPI | MPI | |