Hi, there are no dumb questions on this forum !!
First the model computes the atmosphere datas and then the ocean datas: the ocean datas are computed faster than the atmosphere datas that\'s why you think the increment is 1 hour.
But in fact, the increment (called timestep) is 1/2 hour for both the ocean and the atmosphere.
An extract from the Model introduction page:
\"The coupled model runs asynchronously, which means that the atmosphere model runs first for some time then the ocean model runs for some time, taking turns. In the case of the model used in the climateprediction.net experiment, the individual components run for one day at a time.\"

RAC is the average credit for one day. As it\'s a mean value, it\'s going up and down slowly, but it\'ll stabilize.
HTH

Given that the work units are so long, it\'s always a good idea to take a backup of the c:\\program files\\boinc directory after shutting down the model. That way if something happens to the work unit, you can resume it from the backup.