RTX64 RTOS, Real-Time Solution for Windows 10



RTX64 is a key component of the IntervalZero RTOS Platform that supports determinism or hard real-time on multi-core processors while co-resident with the Windows operating system.  The combined solutions deliver a world-class user experience yet outperform real-time hardware such as DSPs, FPGAs, and MCUs and reduce the development costs for systems that require determinism or hard real-time. Symmetric multiprocessing-enabled RTX64 takes full advantage of 64-bit memory and performance capabilities. Uniquely, the RTX64 RTOS scheduler enables embedded real-time applications to directly access the 512GB of addressable physical memory available on 64-bit Windows. This is critical to modern-day real-time systems and represents a gigantic leap from the 4GB physical memory limit of traditional 32-bit Windows systems. The 4GB barrier has stymied innovation in many industries that depend on real-time systems and that require memory access far beyond 4GB.


    • Guaranteed Precision – set timer periods down to 1 microsecond, and Interrupt Service Thread (IST) latencies of less than 10 microseconds 
    • Separation from Windows – Windows processes cannot interfere with real-time applications 
    • Scalability – one scheduler is used across all real-time processors. Symmetric multiprocessing (SMP) aware scheduler utilizes both priority-driven and pre-emptive algorithms to ensure critical thread context switches; and yields to threads of high priority occur in the sub-microsecond range


    • Flexibility to configure how much real-time processing capability is used (1 to 63 processors) 
    • Full control of real-time process threads with the ability to load balance as needed. RTX64 provides the ability to set thread and interrupt affinities 
    • With Windows failure, shutdown handlers allow RTX64 applications to continue to a safe shutdown 


    • Use a single operating system for applications. RTX64 is supported on Windows 10 
    • Use commercial off-the-shelf (COTS) target system; no special hardware required 
    • Use one development environment – Visual studio 2015, 2017, and 2019 
    • Use common languages (C/C++) for Windows and real-time applications 
    • Use common Win32 API; same code can be run as a Windows or real-time process 
    • Use managed code for Windows application and still communicate with your real-time applications 
    • No driver model to follow; the real-time process can talk directly to hardware 
    • Use standard IPC communication between Windows applications and real-time processes (events, mutexes, and semaphores) 
    • Use shared memory between Windows and real-time process for sharing of data

Reduce Costs

    • Eliminate additional system to perform the HMI 
    • Eliminate proprietary controller and communications cards 
    • Improved asset utilization: Take advantage of underused multi-core capacity
    • Reduced manufacturing costs and fewer physical parts Improve 


    • Eliminate some inventory costs and reduce maintenance costs 
    • Field upgrades are accomplished through software download rather than board replacement


Key Features

Real-time Runtime

    • Scalable from 1 to 63 real-time processors
    • SMP aware scheduler utilizes both priority-driven and pre-emptive algorithms to ensure critical thread context switches; and yields to threads of high priority occur in the sub-microsecond range
    • Configurable thread and interrupt affinity
    • Configurable timer period
    • Ability to attach to line-based and message-based (MSI/MSI-X) interrupts
    • Shutdown handling on Windows STOP or shutdown
    • Deterministic memory
    • Access to Windows file system and registry
    • Ability to set Search paths for process creation and loading of RTDLLs
    • Dynamic-link library support through RTDLLs, which can be loaded implicitly or explicitly
    • Ability to profile application behavior by monitoring internal objects and custom events
    • Real-time Inter-Process Communication between Windows user processes and real-time processes
      • Native and managed interface for 32-bit or 64-bit Windows processes
      • Objects available: events, mutexes, and semaphore
      • Data sharing through shared memory
    • Real-time Inter-Process Communication between Windows kernel drivers and real-time processes
      • Native interface for 64-bit Windows drivers
      • Objects available: events, mutexes, and semaphore
      • Data sharing through shared memory
    • RTX64 Network Abstraction Layer (NAL) provides the following networking capabilities to the RTX64 Subsystem:
      • Per-frame callbacks for high performance, low latency transmit and receive at Layer 2
      • Ability to transmit Ethernet frames close to line-speed
      • Provides burst transmission of Ethernet frames allowing line speed with small packets
      • Supports zero-copy when transmitting multiple frames
      • Supports IEEE-1588 timestamping
      • Network drivers for a number of common Network Interface Cards 
      • Enables the use of NIC hardware queues
      • Supports polling of devices
    • Windows user groups for limiting access to RTX64 features 
    • Tools and Utilities
      • Activation and Configuration – activate subsystem components and configure RTSS cores
      • Control Panel – configuration the subsystem
      • Console – display print messages
      • SRTM – view system timer to timer handler response on a given core
      • KSRTM – view system timer to interrupt service routine (ISR) response
      • Latency View – view and compare system timer response latencies on multiple cores at the same time
      • Task Manager – display a list of running RTSS processes and Windows processes and drivers linked to RTX64, also display pre-process, -thread, and –processor CPU usage
      • Monitor – configures profiling of RTSS
      • RTX64Objects – view internal objects and states
      • RTX64MSpaces – view internal memory allocations

Software Development Kit

    • Headers and libraries for application development
      • Real-time API (RTAPI) similar to Windows Win32 API
      • Real-time Kernel API (RTKAPI)
      • Real-time Network API (RTNAPI)
      • Real-time Network Driver API (RTNDAPI)
      • Managed Code Framework (IntervalZero.RTX64) – Subsystem setup and configuration through managed code interface
      • Native framework – Subsystem setup and configuration through C/C++ interface
    • Microsoft Visual Studio 2015, 2017, and 2019 support
      • Wizard for application and DLL development 
      • API Code snippets
      • C-Runtime support
      • Local and remote debugger support via launch within Visual Studio 
      • Local and remote attach support
    • Microsoft WinDbg extension and RTSS symbols
    • Percepio Tracealyzer for RTX64 – graphical tool to analyze monitoring data
    • Sample source to show basic concepts

Product Documentation

    • Documentation consisting of installation and user guides, API references, and details on real-time programming concepts

Additional Purchasable Features

RT-TCP/IP Stack 

    • The RT-TCP/IP Stack provides the following networking capabilities to the RTX64 Subsystem:
      • TCP/UDP/IP networking for RTX64 processes
      • Support for IPv4 and IPv6
      • Winsock support
      • RAW Sockets
      • MAC layer filtering
      • Virtual Network – point to point connection between Windows and RTSS
      • Utilities (RtssArp, RtssIpConfig, RtssPing, and RtssRoute)

RTX64 Vision

    • RTX64 Vision provides functionality for using GigE Vision Cameras within the real-time RTX64 environment:
    • Real-time GigE Vision filter driver
      • Camera Setup Tool
      • Real-time GigE Vision Interface & Communication library
      • Built version of OpenCV for use with RTSS Vision applications