GPU Passthrough on Proxmox: Windows 11 LTSC vs Ubuntu 24.04 - A Real-World Experience

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lopezoa2003

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Jun 17, 2026
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GPU Passthrough on Proxmox: Windows 11 LTSC vs Ubuntu 24.04 - A Real-World Experience​

Executive Summary​

Bottom line: Windows 11 LTSC is significantly more stable and easier to configure for GPU Passthrough than Ubuntu 24.04, especially if your goal is gaming, remote streaming, or professional graphics work.
Click to expand...

Technical Comparison Based on Real-World Experience​

[th]
Aspect​
[/th][th]
Windows 11 LTSC​
[/th][th]
Ubuntu 24.04​
[/th]​
[td]Ease of Installation[/td][td]⭐⭐⭐⭐⭐ (Straightforward)[/td][td]⭐⭐⭐ (More complex)[/td] [td]Driver Stability[/td][td]⭐⭐⭐⭐⭐ (Very stable)[/td][td]⭐⭐⭐ (Potential regressions)[/td] [td]Graphics Performance[/td][td]⭐⭐⭐⭐⭐ (Optimal)[/td][td]⭐⭐⭐⭐ (Good, but nuanced)[/td] [td]Remote Streaming (Parsec/Sunshine)[/td][td]⭐⭐⭐⭐⭐ (Works perfectly)[/td][td]⭐⭐ (Screen capture issues)[/td] [td]HDMI Audio[/td][td]⭐⭐⭐⭐⭐ (Plug and play)[/td][td]⭐⭐⭐ (Requires extra config)[/td] [td]NVENC Support[/td][td]⭐⭐⭐⭐⭐ (Full performance)[/td][td]⭐⭐⭐ (Limited on some distros)[/td] [td]Full VRAM Access[/td][td]✅ 6 GB detected[/td][td]✅ 6 GB detected[/td] [td]DirectX/Vulkan[/td][td]⭐⭐⭐⭐⭐ (DirectX 12.1)[/td][td]⭐⭐⭐⭐ (Vulkan, but with issues)[/td]

Windows 11 LTSC: The Experience​

✅ What Worked Perfectly​

  1. NVIDIA Driver Installation:
    • Download from official site → run .exe → reboot
    • Key point: The driver installed on the first try with no errors
    • Version: 32.0.16.1062 (June 2026) - very recent
  2. GPU Detection:
    • Windows immediately recognized the GTX 1660 SUPER
    • Full 6 GB VRAM available from the start
    • DirectX 12.1 with all features enabled
  3. HDMI Audio:
    • hostpci0: 02:00.0,pcie=1,x-vga=1 and hostpci1: 02:00.1,pcie=1
    • Audio worked without additional configuration
  4. Remote Streaming (Parsec):
    • Worked on the first try after email verification
    • NVENC active and working with 3% usage at idle
    • Low latency (~5-15ms on local network)
  5. No HDMI Dummy Plug Required:
    • With vga: none configuration, the VM booted with stable HDMI output
    • This was a very pleasant surprise

⚠️ What Needed Attention​

  1. NVIDIA Error 43:
    • Solved with the registry fix I shared
    • AdapterType=00000004 and EnableMsHybrid=00000001
  2. Sunshine Ports:
    • Had to open UDP and TCP ports in the firewall
    • netsh advfirewall firewall add rule name="Sunshine UDP" dir=in protocol=udp localport=5353,47998,47999,48000,48002,48010 action=allow
  3. Sunshine + Windows 11 LTSC:
    • Required manual sunshine.conf configuration
    • Eventually, Parsec was simpler and more stable

Ubuntu 24.04: What Didn't Work As Well​

❌ Issues Encountered (Based on Previous Experience)​

  1. NVIDIA Drivers:
    • More complex installation (requires PPA or manual .run)
    • Potential conflicts with nouveau requiring blacklist
    • Regressions on newer kernels
  2. Remote Streaming:
    • Sunshine had issues capturing the screen on Wayland
    • DuplicateOutput() test failed [0x80070005] - Access denied
    • Dependency on X11 vs Wayland
  3. HDMI Audio:
    • Requires additional PulseAudio/PipeWire configuration
    • Not plug and play like Windows
  4. NVIDIA NVENC:
    • Sometimes not detected properly on Linux
    • Limitations with some encoders (AV1 on GTX 1660 SUPER not supported)

Performance Test Results (Real Data)​

On Windows 11 LTSC:​

text
GPU: NVIDIA GeForce GTX 1660 SUPER
VRAM: 6.0 GB (100% available)
DirectX: 12.1 (FL 12.1)
Driver: 32.0.16.1062 (11/6/2026)
Temperature: 40°C (at idle)
GPU Usage: 2-3% (at idle)
NVENC: Active (3% at idle)

On Ubuntu 24.04 (Expected Values):​

text
GPU: NVIDIA GeForce GTX 1660 SUPER
VRAM: 6.0 GB (theoretically available)
Vulkan: 1.3 (requires configuration)
Driver: 550.x (or similar)
Temperature: Similar to Windows
GPU Usage: Variable
NVENC: Available but with limitations

Conclusion: Which One to Choose?​

Windows 11 LTSC Wins For:​

  • ✅ Gaming (DirectX 12.1, better compatibility)
  • ✅ Remote Streaming (Parsec/Sunshine work better)
  • ✅ Video Editing (NVENC optimized for Adobe/Premiere)
  • ✅ Professional Work (Guaranteed stability)
  • ✅ Ease of Use (Simpler installation)

Ubuntu 24.04 For:​

  • ✅ Software Development (Native Linux environment)
  • ✅ AI/Machine Learning (CUDA well supported on Linux)
  • ✅ Servers (Lower resource consumption)
  • ✅ Containers (Native Docker/LXC)

Recommendations for the Community​

If You Choose Windows 11 LTSC:​

bash
# Recommended VM configuration
bios: ovmf
machine: pc-q35
hostpci0: 02:00.0,pcie=1,x-vga=1
hostpci1: 02:00.1,pcie=1
vga: none
cpu: host,hidden=1,flags=+pcid
args: -cpu host,+kvm_pv_unhalt,+kvm_pv_eoi,hv_vendor_id=proxmox

NVIDIA Error 43 Fix (Windows Registry):​

reg
Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\nvlddmkm]
"AdapterType"=dword:00000004
"EnableMsHybrid"=dword:00000001

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0000]
"AdapterType"=dword:00000004
"EnableMsHybrid"=dword:00000001

For Remote Access:​

  • Parsec: The simplest and most stable option
  • Sunshine + Moonlight: Good alternative (requires more setup)
  • ZeroTier: Perfect for remote access without opening ports

My Personal Experience​

*"After configuring both systems on the same hardware (Proxmox 9.2.3, GTX 1660 SUPER), Windows 11 LTSC was significantly more stable. Driver installation was trivial, HDMI audio worked flawlessly, and Parsec gave me an impeccable remote experience. On Ubuntu, I had to deal with screen capture issues, Wayland/X11 configurations, and audio never worked as well as on Windows."*
Click to expand...

Final Verdict​

Windows 11 LTSC is the recommended choice for GPU Passthrough if your priorities are:
  • Stability
  • Graphics Performance
  • Remote Streaming
  • Gaming
Ubuntu 24.04 is viable, but requires more configuration time and is not as stable for intensive graphics applications.

Quick Reference Table​

[th]
Feature​
[/th][th]
Windows 11 LTSC​
[/th][th]
Ubuntu 24.04​
[/th]​
[td]Initial Setup Time[/td][td]~30 minutes[/td][td]~1-2 hours[/td] [td]Driver Installation[/td][td]✅ Simple[/td][td]⚠️ Complex[/td] [td]HDMI Audio[/td][td]✅ Works out of box[/td][td]⚠️ Needs config[/td] [td]Remote Streaming[/td][td]✅ Excellent[/td][td]⚠️ Hit or miss[/td] [td]Error 43 Fix[/td][td]✅ Registry fix[/td][td]N/A[/td] [td]NVENC Performance[/td][td]✅ Full[/td][td]⚠️ Limited[/td] [td]Gaming Compatibility[/td][td]✅ Excellent[/td][td]⚠️ Good via Proton[/td] [td]Stability[/td][td]✅ 10/10[/td][td]⚠️ 7/10[/td]

Acknowledgments​

To the Proxmox community and everyone who shares their knowledge. I hope this experience helps others make the best decision for their projects.

Useful Links​

Key Takeaways​

  1. Windows 11 LTSC is the path of least resistance for GPU passthrough
  2. Ubuntu works but requires more patience and troubleshooting
  3. Parsec + ZeroTier is the most reliable remote streaming combo
  4. The vga: none trick eliminates the need for HDMI dummy plugs
  5. The NVIDIA Error 43 registry fix is essential for Windows VMs
 
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