It should be noted that while the Xbox One's hard drive can be swapped out, doing so will void your warranty. For the sake of comparison, the video shows speeds for the Xbox One's on-board Samsung OEM 500GB hard drive, as well as a Seagate 1TB hybrid SSHD and a Samsung 500GB EVO SSD.
"Brian Williams" demonstrates in the video that booting to the main Xbox One home screen is about 10 percent faster with a new hard drive. What's more, the system was able to load one level of Call of Duty: Ghosts 20 percent faster once the on-board hard drive was removed and replaced.
Getting the Xbox One to work with a new hard drive also requires formatting and installing the replacement drive. Since the Xbox One does not officially support swapping in a new hard drive, there are no official instructions on how to do so, though "Brian Williams" has also provided a guide for this.