Setting up a dual PC stream uses a capture card to split the workload—your gaming machine runs the game while a second PC handles encoding and broadcasting to Twitch or YouTube.
Running a stream that looks smooth while you play demanding games usually takes more than one machine. Learning how to dual PC stream solves the performance tug-of-war—your gaming PC runs the game, and a second computer handles encoding, overlays, and broadcasting. With the right capture card, a few cables, and some settings tweaks, you can offload the heavy lifting and keep both the game and the stream running well.
What Hardware Do You Need for a Dual PC Stream?
A dual PC stream needs a capture card (external or internal), two Windows PCs, an Ethernet cable for stable network transfer, and a 3.5mm AUX cable for game audio. The gaming PC needs a dedicated GPU with an available HDMI output, and the streaming PC requires a USB 3.0 port for an external card or a PCIe slot for an internal one.
External cards like the Elgato HD60 X are the most common starting point—they connect via USB 3.0 to the streaming PC and take HDMI input from the gaming GPU. Internal cards such as the NZXT Signal install directly into the streaming PC’s motherboard and offer a cleaner cable path. Both work at 1080p 60 FPS, and the choice mostly comes down to portability versus a permanent install.
| Component | Recommended Model | Price (USD) |
|---|---|---|
| External Capture Card | Elgato HD60 X | ~$150–$170 |
| Internal Capture Card | NZXT Signal | ~$100–$130 |
| HDMI Cable | High-Speed HDMI 2.0 | $10–$20 |
| USB Cable | USB 3.0 (included with card) | Included |
| Ethernet Cable | Cat 6 | $10–$25 |
| Audio Cable | 3.5mm AUX male-to-male | $5–$10 |
Step 1: Connect the Capture Card
Plug an HDMI cable from your gaming PC’s GPU output into the capture card’s HDMI IN port. Then connect the capture card to your streaming PC—via USB 3.0 for an external card, or by seating it in the PCIe slot for an internal one. If your card includes an HDMI OUT port, you can connect a second monitor there to view the game directly on the streaming PC’s desktop without adding input lag.
Step 2: Configure the Gaming PC Display
On the gaming PC, right-click the desktop and open Display Settings. Scroll down to the display list and locate the capture card—it appears under the manufacturer’s name, such as “Elgato” or “Signal.” Select “Duplicate these displays” so your gaming monitor and the capture card show the same image. Confirm your primary monitor is set as the Main Display. Choosing “Extend” instead of “Duplicate” leaves the capture card feed blank, and that is the single most common setup mistake.
Intel’s official guide confirms this display duplication step is required for the capture card to receive a usable signal. Without it, the streaming PC sees nothing.
Step 3: Set Up OBS on the Streaming PC
Open OBS Studio on the streaming PC. In the Sources panel, click Add and select Video Capture Device. Choose your capture card from the dropdown menu—the game preview should appear in the OBS window if everything is wired and configured correctly.
Go to Settings > Audio and set the Auxiliary Audio input to the streaming PC’s line-in port, which is where the game audio will arrive. Then connect both PCs to the same router via Ethernet cables, and in Windows Firewall allow OBS through both public and private network profiles so the stream data can flow freely.
How Do You Route Audio Between Two PCs?
The most reliable method is a 3.5mm AUX cable running from the gaming PC’s line-out or headphone jack to the streaming PC’s line-in. Once connected, set that line-in as the audio source in OBS’s Auxiliary Audio setting. If both PCs are on the same wired network, Wavecast (beta) can send audio over the network without a physical cable—this is useful when the gaming PC already uses its audio jack for a headset.
Common Dual PC Streaming Mistakes (and How to Fix Them)
Most dual PC stream problems come down to display mode, audio routing, or network setup. Each has a clear cause and a simple correction that takes seconds to apply.
| Problem | Likely Cause | The Fix |
|---|---|---|
| Black screen in OBS | Display set to “Extend” instead of “Duplicate” | Change to “Duplicate these displays” in Gaming PC Display Settings |
| No game audio in stream | Missing AUX cable or wrong OBS audio input | Connect AUX cable and set Auxiliary Audio to line-in in OBS settings |
| Stream stutters or lags | One or both PCs connected via Wi-Fi | Switch both machines to wired Ethernet |
| OBS does not detect capture card | Driver or capture utility not installed | Install the manufacturer’s software (Elgato 4K Capture Utility, NZXT CAM) |
| Low frame rate in preview | Capture card plugged into USB 2.0 port | Move to a USB 3.0 port (usually blue or marked SS) |
| Game audio echoes | Audio loopback through mixer or cable | Ensure mixer line-out goes to Streaming PC line-in, not back to gaming PC |
Confirm Your Dual PC Stream Setup With This Sequence
Run through this order before you hit broadcast to catch the common failure points before viewers see them.
- Set the gaming PC display to Duplicate mode with the capture card as the secondary display.
- Verify the game preview appears in OBS on the streaming PC.
- Confirm game audio registers on the streaming PC’s audio mixer in OBS.
- Connect both PCs to the same router via Ethernet—not Wi-Fi.
- Allow OBS through Windows Firewall on both machines.
- Paste your stream key from Twitch or YouTube into OBS and run a test recording before going live.
Each of these steps takes under a minute, and skipping any one of them is the reason most dual PC streams fail on the first attempt. Cover them all, and your stream will run as clean as the game itself.
References & Sources
- Intel. “How to Set Up Dual PCs for Streaming.” Official setup guide covering hardware, display duplication, and OBS configuration.
- Elgato. Elgato HD60 X product page. Official hardware specifications and driver downloads.
- NZXT. “Two PC Setup Tutorial – Signal Capture Card.” NZXT’s official installation and configuration guide.
- OBS Project. OBS Studio official site. Free streaming and recording software used on both PCs.