Maximum Memory Size for PXIe-8880RT and PXIe-8861RT

Updated Apr 27, 2023

Reported In


  • PXIe-8880
  • PXIe-8880 Memory
  • PXIe-8861

Operating System

  • LabVIEW Real-Time (NI Linux Real-Time)

Issue Details

What is the maximum memory size for PXIe-8880RT (Phar Lap) and PXIe-8861RT (Linux RT)?


Phar Lap is a 32 bit system so it can support up to 4 GB only. On the other hand, NI Linux RT is 64 bit system. Its memory limit is determined by the maximum memory supported mentioned in controller user manual/specification.

For PXIe-8880 (Phar Lap), the maximum amount of RAM on Phar Lap is 4 GB due to 32 bit OS limitation.
For PXIe-8880 (Linux RT), the maximum amount of RAM on NI Linux RT is 24 GB due to hardware limitations.
For PXIe-8861RT (Linux RT), the maximum amount of RAM on NI Linux RT is 32 GB due to hardware limitations.

Additional Information

It is important to note that the full amount of memories will not be available to RT OS, as some is reserved for other components (e.g. video card, device enumeration, other motherboard requirements). The expected amount is a little less than 3 GB of RAM available to the real-time OS when you use Phar Lap with 4 GB RAM.

LabVIEW Real-Time module installed on your development machine cross-compiles applications for both 32-bit and 64-bit architectures and the application bitness matches the bitness of the RT target distribution. You can monitor memory usage on RT targets programmatically or using utilities like Measurement and Automation Explorer or Distributed System Manager.