Molecular dynamics (MD) simulations of six upgraded empirical force fields were compared and evaluated with short peptides, intrinsically disordered proteins and folded proteins using trajectories of 1, 1.5, 5 or 10μs (5 replicates of 200ns, 300ns, 1μs or 2 μs) for each system. Previous studies have shown that different force fields, water models, simulation methods, and parameters can affect simulation outcomes. Here, the MD simulations were done in an explicit solvent with RS-peptide, HEWL19, HIV-rev, Aβ-40, A-42, phosphodiesterase-γ, CspTm and Ubiquitin using ff99IDPs, ff14IDPs, ff14IDPSFF, ff03w, CHARMM36m and CHARMM22* force fields. The IDP ensembles generated by six all-atom empirical force fields were compared against NMR data. Despite using identical starting structures and simulation parameters, ensembles obtained with different force fields exhibit significant differences in NMR RMDs, secondary structure contents as well as the global properties such as radius of gyration. The IDPs-specific force fields could substantially reproduce the experimental observables in force field comparison: they have the lowest error in chemical shifts and J-couplings for short peptides/proteins, reasonably well for large IDPs and reasonably well with the radius of gyration. A high population of disorderness was observed in the IDPs-specific force field for IDPs ensemble with fraction of β sheets for β-amyloids. The CHARMM22* performs better for many observables, however, still has a preference towards the helicity for short peptides. The results of β amyloid-42 starting from two different initial structures (Aβ421Z0Q and Aβ42model) were also compared with DSSP and NMR data. Results obtained with IDPs-specific force fields within 2µs simulation time are similar, even though starting from different structures. The current force fields perform equally well for folded proteins. The results of currently developed or modified force fields for IDPs are capable of enlightening force field's overall performance for disordered as well as folded proteins, therefore contributing to force field development.