Why the preview lags
Every USB or PCIe card has to compress or copy the picture to the PC, and OBS then draws it. That adds anything from a few frames to over 100 ms: fine for viewers, bad for playing. Capture cards have an HDMI OUT (passthrough) so you can play with no added delay.
Set it up
- Console → card HDMI IN; card HDMI OUT → TV or monitor.
- Play on that screen; keep OBS on a second monitor or minimised.
- Hear the game from the TV or a headset on the console, not from OBS's monitoring, which has the same lag as the preview.
- In the Video Capture Device's properties, set Use buffering to Disable to cut the delay a little more.
If the passthrough itself won't show 120 Hz, VRR or HDR, check the card's passthrough limits; many cards pass through more than they capture, but not all.
Sources: Elgato: Set up Game Capture 4K S with PS5; OBS forum: Video falling behind audio ("Use buffering"). Checked November 13, 2026.