A document authored by Microsoft engineer, reveals that "USB Mass Storage Device Support on Xbox 360" will coming in Spring 2010 "increased market penetration of high-capacity, high throughput USB mass storage devices, a 2010 Xbox 360 system update" will allow consumers to save and load game data from USB devices. Once the update occurs, Xbox 360 owners will be able to download Xbox Live Arcade games, Xbox Live Indie games, Games on Demand, DLC and Title Updates to the storage device. "USB storage devices may, however, have far greater memory capacity than MUs (largest MU is 512 MB), and may therefore support previously infeasible operations-such as installation of full disc-based title." USB mass storage device must be at least 1GB and the system will do a compatibility check. "The system partition occupies 512 MB of space, and by default consumer partition occupies remainder of device capacity, or 16 GB, whichever is smaller." Upon inserting a blank USB storage device, "consumers are offered two choices: 'Configure now' or 'Customize'." "Configure now" option will use "entire device capacity, up to maximum of 512 MB plus 16 GB" meaning, regardless of overall size of the device you're using, Xbox will only enable 16 GB of usable, non-system storage. "Customize" option will allow you to "preserve some pre-existing, non-console data on the device" such as music.