Quest 3 Unity preview — persistent lag/low FPS via Air Link AND Link Cable
Hi everyone,
I'm struggling with a very frustrating issue previewing my Unity Scene on my Meta Quest 3, and after a lot of troubleshooting I'm out of ideas. Hoping someone here has seen the same pattern.
When I hit Play in Unity with the Quest 3 as the PC-VR headset, the preview is laggy, stutters heavily, and runs at a very low frame rate, sometimes so bad it's impossible to test anything. Sometimes, even the Quest Link menu is already very laggy. The strange part is that it's not consistent:
- Sometimes the preview starts perfectly fine.
- Then if the HMD goes inactive (I take it off while editing in Unity for a bit) and I put it back on, the lag comes back.
- Sometimes it's bad from the very first Play.
- Occasionally it just works for a whole session.
What I've already ruled out / tried
- Air Link / network: I initially thought it was bandwidth, but my WiFi is over 300 Mbps, and my PC is on 1 Gbps Ethernet to the router. Hard to see how that's the bottleneck.
- **Link Cable:** Switching to a wired Link Cable makes **no difference** — same lag pattern. So it's not a wireless issue.
- OculusDash.exe: I read that other Quest 3 Link users have had laggy performance caused by OculusDash.exe. Adding a firewall rule to block it sometimes fixes the lag. Then the problem comes back, and toggling the rule on/off sometimes helps again. Not reliable.
- Meta Horizon Link app: Keeping the Meta Horizon Link desktop app open and clicking on the currently active device sometimes resolves the lag. Again — sometimes, not always.
- Audio bug (bonus): Even when the preview is running fine, the audio output keeps switching on its own between HMD speakers and PC speakers, without me selecting that. Happens mid-session.
- Meta XR All-in-One SDK / Simulator: I tried installing it so I could use the XR Simulator and bypass the HMD preview, but it caused compilation errors in my Unity project, so I had to remove it completely. I'm currently only able to preview through the HMD directly.
- PC requirements: I've verified my PC meets all the Meta PC VR minimum/recommended specs (specs below).
Environment
- Unity 6.3 LTS (6000.3.5f2)
- Meta Quest 3, latest firmware
- Meta Quest Link / Meta Horizon Link PC app, latest version
- Both Air Link and Link Cable tested — both show the issue
My PC specs:
- OS: Windows 11 Pro 64-bit (Build 26200)
- CPU: AMD Ryzen 5 3600X (6 cores / 12 threads, 3.8 GHz base)
- GPU: NVIDIA GeForce RTX 5060 (8 GB VRAM), driver 32.0.15.9186
- RAM: 16 GB DDR4 (2× 8 GB Crucial BLS8G4D240FSBK @ 2400 MHz)
- Network: 1 Gbps Ethernet (Realtek PCIe GbE), WiFi 300+ Mbps
- Also listed as a display adapter:"Meta Virtual Monitor" (driver 5.3.57.114) — installed by the Meta software
I'd really appreciate any pointers! This is slowing down my iteration loop in Unity. Thanks!