Looking at both the USB and the storage system of the Xbox, since they are both intertwined and there are differences across the major revisions of the Xbox 360
Background: Xbox Original
To understand the logic of the Xbox 360 storage, you have to look at the past. The original Xbox was one of the first consoles to include an internal hard drive as standard which allowed for storage of game saves, music that could be ripped from an audio CD, or DLC that could be downloaded from Xbox Live. For regular users this meant you did not have to worry about memory cards since the Xbox had plenty of internal storage for game saves and since this was on a hard drive rather than NVRAM like the Sega Saturn, which means saves could be lost should the internal battery die.
Unfortunately the hard drive in the Xbox was one of the more expensive components of the Xbox, and this was one of the reasons the Xbox never made any profit for Microsoft. With this in mind the 360 would be designed over two storage options:
- A basic version that would mirror the storage options of the PlayStation 2/GameCube, where there would be no internal user storage, but an external memory unit would be used instead. The user would still have the option to add a hard drive should they run out of space on the memory unit.
- An premium version that had a internal (or sideloaded) hard drive that brought all the benefits of the hard drive in the original Xbox.
Giving the end user choice may have been a good idea in hindsight, however there were issues and limitations that followed, which will be discussed later.
Type’s of storage available on the 360
Xbox Memory Unit: Offered from 2005 – 2010 and was the primary storage option for the initial core and arcade consoles, available in capacities up to 512GB, designed to be plugged into the front of the 360 and internally use USB, like the original Xbox memory unit. These are not directly compatible with the 360 S models since they lack the ports, however thirds party adapters are available that allow these old memory units to be uses on the S models.
You cannot use an original Xbox memory unit on the 360, or vice versa. Even though they both use USB and are formatted to FATX. No reason has been given for this as this could allow for the original Xbox saves to be migrated over to the Xbox 360.
For the early 360 models without a hard drive, the NXE made these memory units mandatory, since portions of the dashboard are stored on this memory unit.
USB Mass Storage: This option was introduced around 2010, before the launch of the S consoles. You can connect a USB memory stick or an external hard drive and use it as additional storage for game saves, DLC or for games themselves (both downloaded and installed of the DVD). Ideally you were limited to 4GB of storage, this was later increased to 16GB, then 32GB and then to 2TB following the release of the Xbox One.
Not all devices can be used, USB flash drives that are not fast enough will not be approved for use, since the Xbox 360 performs a speed test when initializing the storage. This is because some games may malfunction if they cannot access the data fast enough.
Xbox Hard Drive: Generally the most popular form of storage since its fast and easy to set up, but there are some caveats. First was the hard disk design changed from the original models to the S model, whilst the drives are the same internally and could open the case and manually swap the drive over. This is because the hard disk enclosure was redesigned, on the original models the hard drive was connected either on top or on the side depending on the orientation your 360 console was in, whilst the hard drive for the S model was designed to slot inside the console itself.
Unfortunately you cannot use your own hard drive since it has to be formatted and partitioned using Microsoft proprietary format, and Microsoft has not officially released a formatting tool. If you wish to use your own HDD you must softmod the console, or reflash the hard drive itself to make it appear as a Microsoft drive, for which you are limited to 500GB capacity as this was the largest hard disk Microsoft had released for the 360.
The hard drive is the only storage medium that allows for backwards compatibility for original Xbox titles, since these games were reliant on using the hard drive for caching and user storage. These games will not run if the Xbox 360 does not have a hard drive. Some third party hard drives can also cause issues as they lack the partition 3 that stored the Xbox emulation and game data. This will need to be restored manually be the user.
Internal Flash storage: This was available for Arcade models released after 2008 that did not come with a hard drive. These models have either 256MB or 512MB of internal storage that was used for the dashboard, which became essentially when the NXE dashboard was released. Memory units and hard drives could still be used for these models. With the release of the 360 S, the 4GB model came with internal storage that was really a USB drive mounted internally to the console, like the Wi-Fi adaptor. This internal storage behaves like the memory unit. Some users have been able to modify and replace this internal storage.
HD-DVD: This addon also came with a built in memory unit, but was designed to be connected to the rear of the console and was intended to store a copy of the HD-DVD movie player. Not much is known about this unit so for now I wont discuss it further.
|Memory Unit||USB Storage||SATA Hard Disk|
|Capacity||Upto 1GB (512Mb per memory unit, upto 2 can be connected)||Up to 4TB, upto 2 can be connected at once||Upto 500Gb for an unmodified console|
|Speed||Unknown, less than 480Mbps||Up to 53MB/s (480Mbit/s) shared between different USB devices||Up to 150MB/s (1.5Gbit/s)|
|Availability||Original models only, S model requires an adaptor||All Models||All Models|
|Can be used for||Saves, Music, DLC, Apps||Game installs, Saves, Music, DLC, Apps||Game installs, Saves, Music, DLC, Apps|
Game Installs: Games than can be installed from the DVD drive, this also covers games downloaded from Xbox Live using the games on demand service
Maximum Storage: Theoretically the maximum storage for the Xbox 360 is 5.505TB, with a 500GB SATA HDD, two 2TB USB drives/HDD and two 512MB memory units, along with a 4GB internal flash memory assuming a basic S model is being used. I’d say that’s enough for the entire Xbox 360 game library.
The amount of USB ports vary on the different models
USB 1 – Rear of the console
USB 2/3 – Front of the console, hidden behind the flap
USB 4/5 – Used for the Memory units
USB 6 – used on later revisions for internal storage
USB 1/2/3 – Rear of the console
USB 4 – Kinect port
USB 5/6 – Front of the console, hidden behind the flap
USB 7 – internal used for flash storage for 4GB S model
USB 8 – internal, used for WiFi adaptor module (Why not PCI express?)
Good idea to run Kinect games off USB storage?
USB has limited bandwidth which is shared across the different devices that are connected, in the case of the S models this included the internal Wi-Fi adaptor. This could potentially cause issues when running games that use I the Kinect sensor which uses the USB bus, and a USB external drive. There is a theory below that the Kinect/rear USB port has its own dedicated controller/bus, which gives it’s own bandwidth
Are all the USB ports the same?
No, or at least there are certain devices that can only be connected to specific ports:
Kinect – original 360 models: the Rear USB port was designed to run on its own bus, therefore a device connected has the full bandwidth that USB2 can provide which is why Kinect can only be connected to this port for the original models, the other USB ports seems to share bandwidth (possibly along with the memory units, this was referenced on an online podcast (Major Nelson, unfortunately the link is no longer active and does not appear in the podcast archives.)
Memory Unit Adaptors: Although the S models lack the memory unit ports on the front, Datel released a USB to memory unit adaptor that was intended to connect a memory unit to a PC to transfer and backup save files. The side effect of this was the memory unit can be used on the S model XBOX 360, despite Microsoft not officially supporting it. However only the front USB ports can be used, and the icon varies depending on which port you connect to. The left USB ports appears as Memory Unit A, whilst the right appears as Memory Unit B.
USB: I have noticed some differences in behavior between the front and rear ports of my Xbox 360 S, specifically with USB Memory stick when you turn it on. Sometimes of the flash drives are plugged into the rear and you turn it on, the 360 will not detect of mount the rive and you have to unplug and connect the drive before the 360 will recognize it. This never happens when you leave then plugged into the front. However as of 2021 this seems to have been rectified, so maybe a dashboard update has resolved this issue.
External Hard Drives: Use of external hard disks is recommended due to the speed and capacity they provide (external SSD’s can also work but will be heavily bottlenecked, and might be limited by the power that USB2 can provide) However I would advise to avoid the cheaper external hard drives that you will see on Amazon or eBay, purely because they are dumb in the sense that they do not spin the disk down when the Xbox 360 is powered off. They will keep the hard disk spinning constantly despite the host device being powered off, wasting electricity and reducing the lifespan of the hard disk if not property ventilated, essentially they are a false economy. A lot of the branded drives (Western-Digital/Seagate/Samsung) external drives do spin the drive down when the host has powered off and reactivate when they detect the device being powered on.
Xbox 360 Consoles & SKU’s
Xbox 360 Core: Launch entry level model – No internal flash user storage, no hard drive included but can be added later, memory unit required for NXE update,
Xbox 360 Arcade: Replaced the Core model, No internal user storage, No hard drive included but can be added later, memory unit required for NXE update.
Xbox 360 Arcade (Jasper): Same as previous Arcade model but with 256MB onboard user storage, no hard drive included but can be added later, Can take the NXE update without any additional storage needed, 512MB version later available
Xbox 360 Pro: Launch premium model, Shipped with 20GB/60GB hard drive which is required for it to boot post NXE dashboard, No internal flash user storage
Xbox 360 Elite: Revised premium model, Shipped with 120GB/250GB hard drive which is required for it to boot post NXE dashboard, No internal flash user storage
Models from this point forward are Xbox 360 S
Xbox 360 S: Glossy black case (later matte), Shipped with 250GB/320GB/500GB hard drive storage, No internal flash user storage, Requires hard drive to boot
Xbox 360 S: Matte black case, Shipped with 4GB internal flash memory, No hard drive included but has bay area for it to be installed, Hard drive not required to boot.
Xbox 360 E: Available in the same storage configurations as the S models (4GB flash or HDD)
NXE Update and storage: Because the size of the dashboard grew significantly with this update, additional storage was required in order for this dashboard to function. All Xbox 360’s have internal on-board flash memory, even the original core models and the ones shipped with a hard drive however this memory cannot be manipulated by the user. They contain 16MB of onboard flash which contains the dashboard kernel itself and the system software which is required for the 360 to operate. This was increased to 256Mb for the later arcade revisions so they could store the NXE update without the need of external storage. This 16Mb flash cannot be accessed directly by the user and was intended to be used for the dashboard itself