System requirements

System requirements for OnScale are as follows.


To use OnScale, your Windows PC or laptop must meet the following minimum system requirements:

  • Any Intel or AMD x86_64 processor (no 32 bit support)
  • RAM: minimum 4GB; 8GB recommended 
  • HD: minimum 2GB
  • Graphics card: no specific graphics card is required; however, OpenGL 3.0 or above is needed


We have no immediate plans for macOS support. However, if you're a Mac user looking to use OnScale on an Apple device, we recommend that you use Boot Camp to install Windows. This will allow you to install and use OnScale.


A Linux version of OnScale is available to customers with local licenses. Note, this is not as well supported as our Windows version. For more information, please contact us.

Using OnScale with Remote Desktops or Virtual Machines

Remote desktop applications let you connect remotely to another physical system through a network. This generates an application window showing the desktop of the remotely connected system.

When you run OnScale using a remote desktop application, OnScale may terminate and close down. Generally this is due to your remote desktop application not having access to all the functions on the graphics hardware and, in particular, not using the correct version of OpenGL to render graphical elements required by the application.

Before terminating, OnScale will generate a log file (with extension .txt) in the %APPDATA%\OnScale\OnScale folder of the system on which OnScale is installed. This reports some of the basic settings of your remote environment and can be used for debug purposes.


Please locate this file and check the OpenGL version. OpenGL version 3.0 or above is required.

Virtual machines can experience the same issue but there may be settings to allow graphics hardware to be shared between the local and remote environment. This depends on the virtualization method employed so please discuss this with your IT admin to get it set up correctly.

Using the Command Line to Bypass the GUI

Note: The following information applies to customers running simulations locally only.

Often a remote system is a High Performance Computer (HPC) used to execute large simulations. If this is the case for you, then your workflow could be to use the local system for pre-processing the model and the remote system to execute the simulation via the command line. 

Simulations can be submitted to the single and double precision solvers directly via the command line, which bypasses the application's graphical user interface.

For Windows, in the Command Prompt type:

flex_s <path to flxinp file>

flex_d <path to flxinp file>

For Linux, in the Terminal type:

flex_s.e <path to flxinp file>

flex_d.e <path to flxinp file

Note: Use flex_s or flex_s.e for single precision and flex_d or flex_d.e for double precision.