A Double Fourier Series (DFS) dynamic core, developed by Cheong (2006, Mon. Wea. Rev. ), is implemented into a global atmospheric model having a full physics package. The performance of the new model with the DFS core is evaluated against the model frame having a conventional spherical harmonic (SPH) dynamical core. The SPH core is the one in the National Centers for Environmental Prediction's global forecast model. The results from the two models with same physics package are evaluated in various resolutions such as 62, 126, 214, and 426 wave truncation. Verifications are performed in terms of statistical scores, subjective analysis, and model energy spectrum. A seasonal simulation is designed as well. The spectral energy shows a reduction of energy at high resolution when the DFS core is used. The skill of the new model for medium-range forecast as well as seasonal simulation is comparable to that with the SPH core. Most importantly, the DFS core shows clear advantages in computation at high resolutions with compatible prediction skill.