The newly implemented external storage feature on the Xbox One June software update beta preview brought up something rather interesting: many are a bit doubtful about the option to use an external hard disk drive to store games with consoles because of a widespread misconception that the external USB connection is slower than having an internal hard disk drive.
That is indeed a misconception, as confirmed by NeoGAF user Hawk269, who tested his external hard Seagate 4TB hard disk drive against the stock internal hard disk drive of the Xbox One, resulting in loading a level of Ryse: Son of Rome 16 seconds faster. Other users are reporting similar gains with other games in the private beta forums.
The reason behind that apparently paradoxical discovery is actually pretty simple: the Xbox One uses a pretty slow 500 GB 5400 RPM SATA II hard drive. The SATA II connection standard is the clincher, as it’s limited to 3 Gbit/s (300 MB/s) transfer speed. On the other hand the USB 3.0 standard used by external storage has a higher limit of 5 Gbit/s (625 MB/s).
This means that connecting your HDD via USB to the Xbox One will not limit your transfer speed. As a matter of fact, it will raise the limit, and hard disk drives that are faster than the internal one will result in better loading performance despite their external nature.
Of course you still need your external HDD to be faster than the internal one (that’s pretty easily achieved, really), in order to see the benefits of the feature, as a slower hard disk drive won’t effectively use the higher transfer speed limit of the USB 3.0 standard.
It’s a pretty simple mechanic, but considering the widespread misconceptions about external hard drives, it’s an easily overlooked one. If you didn’t know, now you do. You can use an external HDD on your Xbox One without worries, and it has the potential to actually increase your performance. Just pick a fast one, and you’ll be set to see a very visible improvement, especially on games with long load times like Ryse.