System requirements

What a machine needs to run this. The hard requirements are short; the rest depends on what you ask the machine to do at once.

The hard requirements

Operating systemWindows 10 version 1803 or newer, or Windows 11, 64-bit
RightsAdministrator, for the installation
DiskAbout 1.1 GB for the program, plus room for your media
InternetFor the installation (the engine, about 180 MB, is downloaded unless you supply it — see /OBSZIP), and for updates afterwards

On anything older than Windows 10 1803 the setup stops with an explanation.

For each kind of output

You wantYou need
SDIA Blackmagic DeckLink card with the Desktop Video drivers
NDIThe DistroAV plugin and the NDI runtime
A screen or projectorA second display, extended rather than mirrored
StreamingUpload capacity you can rely on continuously
Hardware encodingAn NVIDIA, Intel or AMD card that supports it — it appears by itself

What actually loads the machine

The requirements everybody asks about are processor and memory; the ones that matter are these:

Encoding. Streaming is the heaviest thing a playout does. A hardware encoder moves that off the processor and is the single best thing you can give a machine that streams.

The number of playouts. Each one renders and encodes its own picture. Two lines is roughly twice the work.

What is in the rundown. A fade renders two cues at once. A web page can cost more than a video. Filters cost per frame, on every frame.

The disk. Recording locally while playing from the same disk is fine; doing either over a slow network share is where stutter comes from.

How to know whether a machine is enough

Not from a specification — from the status bar. It reports, per playout, the frames that were missed, and the render lag for the whole program.

Run your heaviest realistic rundown for twenty minutes, streaming and recording at the bitrate you intend, and watch those figures. Zero missed frames means the machine is comfortable. Numbers that climb during transitions mean it is not.

That test takes half an hour and tells you more than any list of minimum specifications could.