1. A method for distributing sheetside processing in a cluster computing printer controller of a print system, the method comprising: receiving a print job comprising multiple sheetsides; and for each sheetside, performing the steps of: determining a probability distribution function (PDf) of a range of estimated RIP completion times for said each sheetside for each processor of multiple processors in the printer controller; and dispatching said each sheetside to a selected processor of the multiple processors based on the PDf such that said each sheetside has the highest probability of completing at a minimum RIP completion time.