A direct current (DC) magnetron sputtering system has been developed at NASA Marshall Space Flight Center for depositing broadband x-ray optic multilayer coatings. The system has the capability to house up to four, 2-in.-diameter direct-cooled DC magnetron cathodes. The 2-in.-diameter cathodes facilitate low-cost, early stage research and development of various types of optical coatings. Despite the small target diameter, good coating uniformity on 4-in.-diameter substrates is demonstrated. Sources of both systematic and random error in the deposition of depth-graded multilayer coatings were identified and compensated for, resulting in the ability to deposit coating that required ∼7.5  h of total deposition time. Final verification of the system was concluded with the deposition of an NuSTAR W/Si depth-graded multilayer coating design (flight recipe 10).