The increasing performance of DKRZ's supercomputers during the last two decades enabled substantial progress in the development of realistic climate models. In 1987, when DKRZ was founded, the CDC Cyber-205 only allowed simulations of either the atmosphere or the ocean. Likewise, the computational grid had to be very coarse, and the length of simulations was limited to a few years.
Since then, each new system at DKRZ has allowed for an extension of the simulation length, for inclusion of more processes and for an increase of spatial resolution with the result of more realistic simulations. But even today, with currently one of the most powerful computer systems worldwide used for earth system research, the resolution and fidelity of climate simulations are still constrained by computational limitations.