"We are not putting a limit on size"
Microsoft's omnipresent inside man Larry "Major Nelson" Hryb has been hanging around on Reddit answering a variety of questions about the incoming system update that will make Xbox One compatible with external storage devices.
According to the Major, your Xbox One will work with both USB-powered drives and drives that require their own power source. "I am using a bus powered drive with no issues," he told fans on one Reddit thread. The drive in question, which Major also posted a link to, is a 4TB Seagate number. He also says that it doesn't matter what format your drive is originally: "When you plug your drive in the first time, the console prepares it for use for storage. From that point forward, you can only use it with an Xbox One."
In response to multiple questions about the maximum drive size allowed, Nelson replied that "we are not putting a limit on size." You can also plug in two drives at once: the console will support up to two USB 3.0 drives, which you can rename to whatever you like.Does that answer all your burning questions about the update? We'll keep an eye on Reddit and update this post as soon as we dig up any more information.