Support and Troubleshooting
Contact Cubix to determine if your notebook computer supports external GPUs.
Power on/off GPU-Xpander Desktop 2 normally.
- With GPU-Xpander connected to the host computer and running, shut down the host normally.
- With GPU-Xpander connected to the host computer and powered down, switch on GPU-Xpander first and the connected host next; both will boot up.
Quickly test that GPU-Xpander works with your notebook or other computer as follows:
- Do not install graphics or other controllers until instructed to do so within this procedure.
- Switch off AC power from the host computer and the GPU-Xpander Desktop 2 but leave the power cord in each connected.
- Install the ExpressCard in the notebook computer's port.
- Using a Philips #2 screwdriver, remove the 4 screws holding the GPU-Xpander top cover in place.
- Connect the external PCIe cable to the ExpressCard port. Warning: Switch off GPU-Xpander power before connecting to or disconnecting from the adapter in the host computer.
- On GPU-Xpander, switch on the AC power switch next to the AC receptacle.
- Power up the host computer. The GPU-Xpander also powers on.
- Confirm that exterior Link LED and the interior Cable LED (P0) are lit green. The enclosure fan should also be spinning. If not, check the following:
- Host computer BIOS settings for CPU and PCIe spread spectrum are set to [Disable]. If not, disable, save settings and exit BIOS, which restarts the computer.
- Confirm that the Cubix adapter is firmly seated in a PCIe slot within the host computer.
- Confirm that both cable connectors are firmly seated to the adapter connectors.
- GPU-Xpander is functioning properly once the Cable Link LED (P0) is flashing green.
- Shut down the laptop computer.
- Switch off GPU-Xpander.
- Loosen the captured screws holding down the GPU-Xpander end brackets.
Install one GPU or identical GPUs in a GPU-Xpander PCIe slot and connect auxiliary power cables if needed. See the image at the right.- Replace the hold-down bracket and tighten the retaining screws.
- Connect GPU video port(s), if present, to monitors. This step is especially important for Linux, because X Windows (X) will crash if you have not connected video ports to monitors. If you cannot connect monitors to installed GPU video ports, you can edit the Device section of /etc/X11/xorg.conf to define which GPU X should use as the primary display device. For example:
Section "Device"
Identifier "Device0"
Driver "nvidia"
VendorName "NVIDIA Corporation"
BoardName "GeForce GTX 480"
BusID "PCI:8:0:0"
EndSection
To determine the BusID for the GPU port you wish to use as the primary display, run the scanpci tool discussed in Step 17. - Power up the laptop computer and GPU-Xpander to confirm that the appropriate slot link LEDs (P1, P5, P7 and/or P9 in the image below) are lit green, which confirms that you have installed the controller(s) correctly in each slot.
- Confirm that your operating system (OS) has detected the new controller(s). For instance, in a notebook running Microsoft® Windows®, check Windows Device Manager. Within Windows, you can also run GPU-Z, a utility available for free download here. In a notebook running Linux, run the following:
root# > XFree86 –scanpci
Read more about scanpci here. - If all the Cable Link and slot LEDs are lit green but your OS does not detect the GPUs, shut down the OS gracefully, power down GPU-Xpander and remove / replace the GPUs. Make sure that you seat each GPU firmly in its slot and that you connect all auxiliary power connectors properly. Switch on GPU-Xpander and boot up the laptop computer.
Install the appropriate graphics or other controller driver(s) using the vendor’s procedure.- If your notebook computer will not boot with one or multiple GPUs in GPU-Xpander, contact the notebook computer's vendor support and ask if your model's BIOS supports external, multiple GPUs with video ports. If not, and a BIOS update to provide such support is not available, shut down both the notebook and GPU-Xpander. Disconnect the cable from the ExpressCard, install the PCIe x1 host interface controller (HIC) in host computer's PCIe slot and follow the procedure for GPU-Xpander Desktop 2 [5.0Gbps] for tower computers here.
- Apple MacBook Pro OS X does not support natively NVIDIA® GPU products. If you want to use a GPU with a MacBook Pro, install NVIDIA Tesla C1060. You can also install GeForce GTX 480 but this disables integrated MacBook Pro video, which means you must connect a display to GTX 480. Download, install and run Boot Camp 3.x, which is free for download (here). With Boot Camp installed, install and run Windows 7 on your MacBook Pro and then install the NVIDIA Tesla C1060 or GeForce GTX 480 driver for Windows 7.
- Confirm that the GPU-Xpander Fatal Error LED is not lit amber. If it is, reboot the notebook computer.
- Switch off AC power to the host computer and the GPU-Xpander 5. Leave the power cords and the external PCIe cable to the host computer port connected.
- Replace the GPU-Xpander top cover as shown in the image at the right and replace the screws holding it in place. Use all of the screws in the bag packed with the GPU-Xpander. Warning: Replace the cover as soon as possible to allow for proper cooling of controllers installed in the unit. Do not run GPU-Xpander without the cover for more than a few minutes.
- Power up the computer and the GPU-Xpander Desktop 2.

The Cable Link LED (P0) inside GPU-Xpander flashes green when connected through an ExpressCard adapter to a notebook computer.
- The Cable Link LED (P0) inside GPU-Xpander shines green, indicating 5.0Gbps transfer, when connected with the host adapter plugged into a PCI Express 2.x slot.
- The Cable Link LED (P0) inside GPU-Xpander flashes green, indicating 2.5Gbps transfer, when connected with the host adapter plugged into a PCI Express 1.x slot or with an ExpressCard adapter plugged into a notebook computer's socket.
The Cable Link LED (P0) and the slot LEDs (P5, P1, P9 and/or P7) inside GPU-Xpander light correctly but the operating system (OS) does not detect installed GPUs.
- Power down the OS, the host computer and GPU-Xpander.
- Remove and replace the GPUs, making sure to seat the GPUs firmly within each PCIe slot and to seat firmly all of the auxiliary power cables into place.
- Power up GPU-Xpander and then power up the laptop computer. When the OS boots, it should detect the GPUs now.
- Some laptop computers, even with an ExpressCard adapter, cannot support external, multiple GPUs due to BIOS limitations. If this is the situation with your notebook or laptop computer, use the procedure for GPU-Xpander Desktop 2 [5.0Gbps] for tower computers here.
The Slot 1, 2, 3 or 4 LEDs (P5, P1, P9 and/or P7) inside GPU-Xpander flash green.
- Download the latest driver for the graphics controller from the vendor's site.
- Install the driver.
- Put a load on the GPUs.
- The P1, P5, P7 and/or P9 LEDs may light steady green, which indicates the links to slots are each 5.0Gbps and that the GPUs are processing a load; however, if these LEDs continue to flash green, it is because the connection through an ExpressCard adapter is 2.5Gbps. The link is not capable of a full PCIe Gen 2 x1 connection of 5.0Gbps using an ExpressCard adapter.
When connected to an ExpressCard in my notebook computer, the Cable Link LED (P0) inside GPU-Xpander flashes green.
- ExpressCard supports only 2.5Gpbs transfer.
- Connect GPU-Xpander to a computer with an adapter in a PCI Express 2.x slot to assure 5.0Gbps transfer to GPU-Xpander.
GPU-Xpander is connected to both power and a host computer. Both are powered up, but GPU-Xpander displays no external link LED and the fan is not spinning:
- Check the internal 10-pin cable connecting the Master Interface Board to the front panel.
- Make sure pin 1 of the 10-pin cable is connected as shown in the image at the right.
If you have warnings in Windows Device Manager, make sure that the following is true:
- You have installed the appropriate Intel chipset utility and other drivers for the computer.
- You have installed other drivers, including third-party graphics drivers, as appropriate.
Before You Contact Cubix
Find the unique serial number (s/n) located on the GPU-Xpander outside cover. Have this s/n ready when you contact Cubix Customer Service.
Fill out and submit the Contact Cubix form.
Email customerservice@cubix.com
Hours 8 a.m. to 5 p.m. Pacific, Monday through Friday
Closed weekends and holidays
USA or Canada Telephone 800.829.0554
International Telephone +011 1.775.888.1000