Connecting Multiple Monitors to A PXIe Controller

Issue Details

I have noticed several PXIe controllers have multiple monitor ports and support the use of dual monitors.

• The PXIe-8880 and PXIe-8881 have a single DisplayPort. Is there a way to connect multiple monitors to a PXIe-8880 or PXIe-8881?
• The PXIe-8861 has two DisplayPorts. Can I connect multiple monitors using these ports?
• The PXIe-8840 has two DisplayPorts. Can I connect multiple monitors using these ports?
• Is connecting multiple monitors going to put an extra load on my PXIe controller CPU?

Solution

PXIe-8881 and PXIe-8880
The PXIe-8881 has an AMD Radeon™ E6465 and the PXIe-8880 has an AMD Radeon™ E6460, both with a DisplayPort 1.2 output from the Embedded GPU. You can daisy-chain multiple monitors to the DisplayPort 1.2 connector.

PXIe-8861
The PXIe-8861 has one DisplayPort 1.1 connector and one DisplayPort 1.2 connector. You can use these ports to connect two monitors without the use of a splitter. You can also daisy-chain multiple monitors to the DisplayPort 1.2 connector.

PXIe-8840
The PXIe-8840 has two DisplayPort 1.2 connectors, so you can use these ports to connect two monitors without the use of a splitter. The PXIe-8840 uses the Intel® HD Graphics controller embedded into its Intel® Core™ i7 5700EQ processor.

Further, it is to be noted that, in the case of using the built-in display output ports, connecting multiple monitors is not going to put an extra load on your CPU as the display signals are not routed through it. Rather, the display signals are routed through GPU only. However, it should be noted that attaching a docking station to extend the display, through one of the USB 3.0 ports might affect your CPU load as USB 3.0 signals are routed through the CPU for processing. 

Refer to Additional Information, the Related Links, and your controller's documentation for further details.

Additional Information

According to the DisplayPort standard, DisplayPort 1.2 enabled products feature a multi-stream technology that allows independent streaming to multiple video displays from a single video output, through the use of monitor hubs or daisy-chainable monitors.

“Daisy chaining” is a term that describes the ability to connect a series of devices together using a single connection between each two devices.  The new DisplayPort v1.2 daisy-chainable displays have both a DisplayPort input and a DisplayPort output. The DisplayPort output connects to the next downstream display.  This cabling arrangement, with one DisplayPort cable between each set of monitors, provides a less cluttered system configuration.

GPUs usually have an inherent limitation in how many simultaneous displays they can drive; some can drive up to three displays, while others can drive four or even six. For example, the AMD Radeon™ E6460 Embedded GPU supports up to 4 monitors. However, adding additional displays would limit the maximum resolution. Refer to Related Links for additional details.

So, even though DisplayPort 1.2 offers the higher pixel rate available, there is a limitation in how many pixels can be sent down the display pipe. This means that while using a single display allows resolutions of up to 3840x2160 or 4096x2160, using two displays limits the maximum resolution for each monitor to 2560x1600.

If you are having difficulties extending the display to multiple monitors, ensure that you have the PXI Peripheral Drivers installed on your system. These downloads are available through our downloads section; search by your model name to find the right download. If your controller uses an Intel® HD Graphics controller, make sure your system has the latest Intel graphics driver. Also, make sure that your Display settings are properly configured in Windows Device Manager to extend the display.

Note: While DisplayPort 1.2 allows for 4K resolution, neither the AMD Radeon™ E6460 nor the AMD Radeon™ E6465 Embedded GPUs support 4K resolutions and the maximum available resolution may be limited by the GPU and/or the display itself.

Note: If you are using a DisplayPort splitter with a USB based power input, it may not work if connected to one of the controller's USB ports. If this happens, test the splitter using an external USB power supply or test it on a different computer to verify the splitter is working fine. If the splitter works fine in other systems or with external power, please report this to NI Support for investigation.