PXI/PXIe Controller RAM with NI Real-Time Phar Lap ETS

Updated Apr 3, 2019

Reported In


  • PXI Controller

Operating System

  • PharLap

Issue Details

  • I am upgrading my PXI controller's RAM from 2 GB, is 4 GB or 8 GB supported?
  • I have a PXI or PXIe RT controller running NI Real-Time Phar Lap ETS operating system. I have 8 GB of RAM installed, but just less than 3 GB of RAM appears in Total Physical Memory from NI-MAX and the NI Web Interface (WIF).


NI Phar Lap ETS (sometimes abbreviated as PharLap), is a 32-bit operating system and can therefore only address 4 GB of RAM. Of this 4 GB, the full amount will not be available to 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.