Networking / UDP latency - Street Fighter 6

Abnormally high latency (~200 ms) in Street Fighter 6 on Linux, while Windows and PS5 show ~1–5 ms under identical local and online conditions

System Information

GPU: Radeon RX 9070 XT (radeonsi, gfx1201, LLVM 21.1.4, DRM 3.64, 6.17.5-2-cachyos)
Driver/LLVM version: 4.6 (Compatibility Profile) Mesa 25.2.5-cachyos1.5
Kernel version: 6.17.5-2-cachyos
Link to full system information report as Gist: https://gist.github.com/sanroxcode/352f59e262d64dd86f4bb8a153b2dd22

Expected Behavior

In a stable local (LAN) or regional online connection, in-game latency should match the actual network ping — around 1–10 ms, as consistently observed on Windows 10 and PS5 under the same physical and network conditions.

Actual Behavior

On Linux systems, Street Fighter 6 shows a stable in-game latency of ~200 ms, even when:

• Playing locally on the same wired network, between two different accounts I own (Steam ↔ PS5);
• Playing online with friends in the same city, who do not use Linux and have stable pings around 5–10 ms.

The issue occurs consistently across multiple Linux distributions and Proton versions, despite extensive testing and network validation.

Steps to Reproduce

1. Install Street Fighter 6 via Steam on Linux (Proton 9.x, Experimental, GE, or native Steam runtimes).
2. Connect PC and PS5 to the same router via Ethernet cable.
3. Log in with two different accounts (one on Steam, one on PS5).
4. Create a private room containing only these two accounts.
5. Observe in-game ping:
   • Linux → ≈ 200 ms
   • Windows → ≈ 1 ms
6. Repeat the test with friends who use Windows or consoles (ping 5–10 ms).
   • The same high-latency behavior persists only on Linux.

System Information / Tested Environments

Network and Hardware Context

• Tests performed on the same computer (dual boot), using wired Ethernet directly connected to the same router.
• No changes to router firmware, cabling, or local network configuration during any test.
• Tests performed in the same house, same network, and under identical physical conditions.
• ISP was contacted to check for possible irregularities; they confirmed that the connection was normal and even reset my signal remotely, but the issue persisted.
• Tested with two different network adapters:
  • One using a Realtek chipset
  • Another using an Intel chipset
  • Both produced the same results (≈200 ms latency in Linux, ~1 ms in Windows).
• Friends do not use Linux — all are on Windows or console systems, yet the same high-latency behavior occurs only on my Linux setups.

Additional Context / Screenshots

Summary

• Network and environment confirmed stable.
• Correct latency in Windows (~1–5 ms).
• Abnormally high latency in Linux (~200 ms).
• Reproduced across three different Linux distributions: Bazzite, Linux Mint, and CachyOS.
• Tested with multiple Proton versions (default, Experimental, GE, native/custom).
• Tested with two different network adapters (Realtek and Intel).
• ISP verified and reset connection, no effect.
• Friends tested on Windows and consoles only (no Linux users involved).
• Problem appears only on Linux, under identical conditions.
• Occurs in both local matches (Steam ↔ PS5 accounts) and online matches with friends.
• I initially migrated to CachyOS after testing Bazzite, thinking the problem might be exclusive to that distro, but the same issue persisted in all three.

The issue is reproducible across different Linux distributions, Proton versions, and network hardware.
It affects in-game latency exclusively on Linux while all other platforms (Windows and PS5) perform normally.