Process intensification in biomanufacturing has attracted a great deal of interest in recent years. Manufacturing platform improvements leading to higher cell density and bioreactor productivity have been pursued. Here we evaluated a variety of intensified mammalian cell culture processes for producing monoclonal antibodies. Cell culture operational modes including fed-batch (normal seeding density or high seeding density with N-1 perfusion), perfusion, and concentrated fed-batch (CFB) were assessed using the same media set with the same Chinese Hamster Ovary (CHO) cell line. Limited media modification was done to quickly fit the media set to different operational modes. Perfusion and CFB processes were developed using an alternating tangential flow filtration device. Independent of the operational modes, comparable cell specific productivity (fed-batch: 29.4 pg/cell/day; fed-batch with N-1 perfusion: 32.0 pg/cell/day; perfusion: 31.0 pg/cell/day; CFB: 20.1 - 45.1 pg/cell/day) was reached with similar media conditions. Continuous media exchange enabled much higher bioreactor productivity in the perfusion (up to 2.29 g/L/day) and CFB processes (up to 2.04 g/L/day), compared with that in the fed-batch processes (ranging from 0.39 to 0.49 g/L/day), largely due to the higher cell density maintained. Furthermore, media cost per gram of antibody produced from perfusion was found to be highly comparable with that from fed-batch; and the media cost for CFB was the highest due to the short batch duration. Our experimental data supports the argument that media cost for perfusion process could be even lower than that in a fed-batch process, as long as sufficient bioreactor productivity is achieved. (C) 2016 American Institute of Chemical Engineers