How do I Disable the GPU in the NI cRIO Performance Controllers?
Hardware: CompactRIO>>Controllers>>cRIO-9034, CompactRIO>>Chassis (Backplanes)>>cRIO-9031, CompactRIO>>Chassis (Backplanes)>>cRIO-9033, CompactRIO>>Chassis (Backplanes)>>cRIO-9030
I am using a NI cRIO-903X and want to decrease jitter in my application that uses control loops rates > 5 kHz. How do I disable the GPU to help with the jitter?
For NI CompactRIO Performance Controllers, the devices can sustain 5 khz rates without tuning. If higher rates are required, an option is to disable the GPU, since it is a component optimized for throughput, not for determinism. Disabling it can give you determinism at > 5khz rates; however this comes at the cost of higher CPU usage since video would be done via the software side without the presence of the GPU.
Note: Another option to be considered to help sustain rates above 5 kHz would be moving the code to FPGA. Please see White Paper: Design and Deploy FPGA-Based Controllers for more information.
Attached to this KnowledgeBase is a compressed folder with the files needed to disable your GPU. Complete the following steps to disable the GPU on your Performance Controller:
The files included in the Disable GPU.zip are 20-intel.conf and Disable_Graphics_Acceleration.cdf. To determine if the file is correctly located on your target, you can navigate to the folder /usr/share/X11 on your controller and see if the file 20-intel.conf exists.
Note: Please note that disabling the GPU will not disable the embedded UI.
White Paper: NI CompactRIO Performance Controller: Performance and Throughput Benchmarks
White Paper: Design and Deploy FPGA-Based Controllers
Report Date: 08/08/2014
Last Updated: 02/23/2015
Document ID: 6O77S4PK