Evaluate the collective function of references cited together in a given text segment.
Classify their combined role into one of the following categories: 'method', 'background', or 'result'.

Text:ISCA 2012 paper [66], simply adding more banks to the memory subsystem comes at signi cantly high costs or reduced performance regardless of the way it is done: more banks per chip, more ranks per channel, or more channels.
Category: