XG Mobile Dock

XG Mobile Dock

This open source hardware allows you to connect any PCIe card to an ASUS ROG device with the XG Mobile connector.

The standard variant is a drop-in replacement PCB for the XG Station Pro Thunderbolt 3 eGPU dock. It contains a built in USB 3.1 Gen 2 hub and a USB PD charger.

The lite variant is a standalone board that is compatible in dimensions with the ADT-UT3G. It requires a standard ATX power supply and passes through the USB to an external port.

Features

• Up to PCIe 4.0 x8 support for 2021/2022/2023 ROG Flow
• Up to PCIe 4.0 x4 support for 2023 ROG Ally
• MCU handling cable detection and LEDs
• 65W USB PD charger (standard variant)
• 2 USB-C ports connected to a USB 3.1 Gen 2 hub (standard variant)
• 300W DC-DC power supply (standard variant)

Getting Started

1. Build the PCB
2. Flash the board
3. Install the software

Flashing Firmware

Lite boards only need to flash STM32 while the standard board requires writing two SPI flash as well.

STM32 MCU

1. Download XG_Mobile_Dock_MCU.bin from the latest release or build your own.
2. Download and install ST32CubeProgrammer.
3. Connect your ST-LINK v2 to your computer. Note if you are using a cheap clone from Amazon or Aliexpress, the pin numbers printed on the device may be incorrect.
4. Connect the SWDIO, SWCLK, and GND pins to J10 on the board to the ST-LINK v2. Do not connect +3V3. If you are using an official ST-LINK, you will need a jumper wire from VAPP (pin 1) to VDD (pin 19).
5. Ensure the board is powered on so it can be programmed.
6. Open ST32CubeProgrammer and go to the "Erasing & programming" page (second icon on the left sidebar).
7. Browse and select the firmware file.
8. Check "Run after programming"
9. Click "Connect" on the right sidebar and then "Start Programming" on the left.

SPI Flash for TI USB PD

We will be using a Raspberry Pi, although most other SBC can also work as well as dedicated SPI flashers.

1. Enable the SPI interface on the Raspberry Pi.
2. Connect GND (Ground), SS (SPI0 CE0), CLK (SPI0 SCLK), MISO (SPI0 MISO), and MOSI (SPI0 MOSI) on J9 to the Raspberry Pi.
3. Open a shell to the Raspberry Pi and install Flashrom: sudo apt-get install flashrom
4. Download XG_Mobile_Dock_Charger.bin from the latest release or build your own.
5. Flash the firmware: sudo flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=1000 -w XG_Mobile_Dock_Charger.bin

SPI Flash for VIA USB Hub

We will be using a Raspberry Pi, although most other SBC can also work as well as dedicated SPI flashers.

1. Enable the SPI interface on the Raspberry Pi.
2. Connect GND (Ground), SS (SPI0 CE0), CLK (SPI0 SCLK), MISO (SPI0 MISO), and MOSI (SPI0 MOSI) on J13 to the Raspberry Pi. Note the order of the pins is different from J9.
3. Open a shell to the Raspberry Pi and install Flashrom if it is not already installed: sudo apt-get install flashrom
4. Download VL822_Q7_9043_Phantom_20220616.bin from the latest release.
5. Flash the firmware: sudo flashrom -p linux_spi:dev=/dev/spidev0.0,spispeed=1000 -w VL822_Q7_9043_Phantom_20220616.bin

Install XGMDriver

XGMDriver tricks ARMORY CRATE software into identifying the custom dock as an official XG Mobile device. Once installed, it should work even if ARMORY CRATE software is updated. You can check out the source code here.

1. Download XGMDriverSetup.exe from the latest release.
2. Run the installer making sure to correctly select AMD or NVIDIA depending on the vendor of the GPU you are installing.
3. If you need to swap between AMD and NVIDIA, uninstall from Control Panel or by running the installer again. Then you can re-install and select the right option.

Troubleshooting

Error 43 or no video output on NVIDIA GPUs

This is a well known issue with NVIDIA eGPUs. Once the eGPU is installed along with the correct drivers, you will need to install this script.

PCIe is only getting 3.0 speeds after hot plugging

You need to restart your device. For some reason, hot plugging results in 3.0 speeds.

Unable to get 4.0 speeds

If you observe any of the following:

• GPU-Z changes between 4.0 and lower versions when under load
• You observe a lot of stuttering or < 10 FPS in 1% lows
• Windows behaves extremely slowly (moving the mouse cursor will take > 1 sec to respond)
• Event viewer for System shows multiple times: "WHEA-Logger Event ID:17 - A corrected hardware error has occurred"

Then the device is having trouble sustaining PCIe 4.0 speeds. This can be caused by any combination of the following issues:

1. The board was not manufactured properly with impedance matching or the high speed connectors were not properly soldered. Verify that the boards were manufactured with the correct specifications and test multiple boards.
2. The GPU is malfunctioning or is not mounted correctly. Make sure you can obtain PCIe 4.0 speeds on a desktop PC.
3. The XGM cable is not connected to the board correctly. Make sure the two 40P connectors are tight and the metal bar is locked over the connector to prevent unintentional loosening. Make sure the shielding screw is tightly screwed to the screw terminal next to the connector. Make sure the cable isn't twisted or bent any more than it needs to be. If the XGM cable came coiled up, try to carefully straighten it.
4. The XGM cable is not manufactured correctly. The official XGM device only supports PCIe 3.0 speeds so the cable is only rated for PCIe 3.0. We found that some cables are easier to get 4.0 speeds working than other cables so there is some manufacturing variance.

You can run FurMark for a long duration and observe the GPU load to check that it is able to maintain 4.0 speeds. If the GPU is constantly trying to switch speeds, you will observe large FPS drops and large dips in the GPU usage percentage. You can also use CUDA-Z to check the access speeds while under load.

If you cannot maintain PCIe 4.0 speeds, you can always do a hot-unplug and hot-plug to force it to run in PCIe 3.0 mode.

No popup when XGM is connected

Sometimes, the device will not be detected and you can flip the lock switch off and on again to force the software to re-detect the device.

"It appears that your XG Mobile is not properly connected..."

If you get a pop-up saying XG Mobile is not properly connected, make sure XGMDriver is installed. If this is still an issue with XGMDriver installed, there is likely a connection issue with the cable.

ASUS Driver install popup on reboot

Re-install XGMDriver to inhibit the ASUS driver popup.

Lite: USB is not detected

The lite board does not have USB orientation detection. Try flipping the USB-C cable upside down and try again.

References

Knowledge base for all things XGM gathered from reverse engineering the hardware and software.

• XGM connector information
• XGM software interfaces
• MCU command interface
• PCB design diary
• Reversed ACPI tables
• Reversed BIOS detection

Related Projects

• Modified Lite design with redrivers for improved performance (not yet working)