If you didn’t already read the What are my setup options? page, there is some important information about video for dual-pc. Highly recommend you go and read that and then come back. I’ll wait.
When going this route, you will need to have an internal or external capture card, and you’ll typically use video cables like HDMI to connect the gaming PC’s graphics card to the streaming PC’s capture card. Plug and play for the most part, and the only configuration you’ll need to do after the fact is set things like resolution, frame rate, color profiles, etc. The three most common methods here are pass-through, display cloning, and OBS full screen preview. I will give you a brief explanation of each of these methods, but please know you’ll have to follow some guides for each of these.
Pass-through is the preferred method and yields the best results. This is when you plug your gaming PC graphics card into the streaming PCs capture card “in” using an HDMI cable. Then, from the streaming PC capture card “out”, another HDMI cable that plugs into your gaming PC main monitor. For 1080p 60fps capture, you can almost always pass-through without issue or advanced configuration. It’s when you get into the 1440p 144hz or higher content that the next two methods come in handy. If you wanted to play games at 1440p 144hz, but stream at 1080p60 or 720p60, you needed to have a graphics card, a gaming monitor, and a capture card all with HDMI 2.0. And of course, HDMI 2.0 cables. The capture card also needs to specify that it can handle that singal.
Display Cloning, also known as “phantom display” method, is commonly used when a creators monitor does not have an HDMI 2.0 port. So you can’t use the pass-through method, or else your 1440p144hz monitor would not function properly. Instead of the cable hookup described above, you only have a single HDMI 2.0 cable that goes from the gaming PC graphics card to the streaming PC capture card “in”. When you do this, the gaming PC treats that connection to the capture card like it’s a virtual monitor, and will be listed as monitor 2 or 3. Your gaming PC thinks it’s there, but physically, it is not. Then, either using Windows display management or nVidia control panel, you clone your primary monitor (monitor 1) to monitor 3, which is the capture card input. Once that is done, and you add the capture card source to OBS, everything on your gaming PC gets sent to the streaming PC. It’s confusing, you’ll have to see it to believe it.
OBS full screen preview is also an option if display cloning isn’t quite working for you. The physical setup with cable hookups is the same as display cloning, however instead of cloning your display with WIndows or nVidia, you run OBS Studio on the gaming PC. The only thing OBS Studio needs is 1 scene and 1 source that captures the gameplay. Then, you use it’s ‘Fullscreen Preview’ option to send the OBS preview to that third ‘virutal’ monitor that got created when you plugged your gaming PC GPU into the streaming PC capture card. This uses little to no resources on the gaming PC, lets you play in high res/fps, and doesn’t give you all the artifacting and screen tearing that display cloning does.
1080p 60fps
1440p 144hz or higher