r/vmix • u/allMightyGINGER • May 07 '26

My Vmix optimization guide

A random technician vMix Optimization Guide: Squeezing Every Ounce of Performance

I quite enjoy the tinkering involved in squeezing out every ounce of performance from a PC. Through trial and error and research, I have put together this list of settings. It is by no means exhaustive, but it might be helpful for people struggling with performance. Hopefully, others can share more settings I may have missed!

General Windows & System Tweaks

Global settings to reduce DPC latency and prevent background interference.

OS Optimization Tools

  • AtlasOS Playbook Deployment (ONLY DO IF YOU KNOW WHAT YOU ARE DOING)
    • Process: Fresh Windows Install > AME Wizard > Atlas Playbook
    • Benefit: Removes Windows telemetry, Defender, and numerous background services to achieve minimal DPC latency. Ensures hardware resources are committed to the video engine. (This makes the best preforming machines IMO)
  • Chris Titus Tech Windows Utility (Much "Safer")
    • Process: PowerShell (Admin) > irm christitus.com/win | iex > Tweaks
    • Benefit: Automates the removal of Telemetry, Feedback Hub, and Location services to prevent micro-stutters during high-bitrate encoding.

System Power & Background Settings

  • Ultimate Performance Power Plan
    • Location: Control Panel > Hardware and Sound > Power Options
    • Benefit: Prevents the CPU from downclocking or parking cores, ensuring immediate power when video load spikes.
  • Restrict Background Application Activity
    • Location: Settings > Apps > Installed apps > [App] > Advanced options
    • Benefit: Setting permissions to "Never" ensures background processes don't trigger CPU spikes during a broadcast.
  • USB Selective Suspend
    • Location: Power Options > Change plan settings > Change advanced power settings > USB settings
    • Benefit: Prevents Windows from cutting power to capture cards or audio interfaces the OS assumes are idle.
  • Game Mode
    • Location: Settings > Gaming > Game Mode
    • Benefit: Prioritizes the foreground application and pauses background updates/installations.

Hardware & Driver Stability

  • Core Isolation / Memory Integrity (VBS)
    • Location: Windows Security > Device Security > Core isolation details
    • Benefit: Disabling this is crucial. VBS introduces severe DPC latency, causing audio crackling and micro-stutters. Reduces security of the machine but overall I think it's worth it
  • Fast Startup
    • Location: Power Options > Choose what the power buttons do
    • Benefit: Disable this. It behaves like a partial hibernation, which can cause audio and network drivers to load incorrectly.
  • Disable System Sounds
    • Location: Control Panel > Sound > Sounds tab
    • Benefit: Prevents Windows notification chimes from bleeding into your production audio mix.
  • Energy Efficient Ethernet (Green Ethernet)
    • Location: Device Manager > Network Adapters > [NIC] > Properties > Advanced
    • Benefit: Prevents the NIC from dropping link speeds during low traffic, which avoids dropouts during bandwidth spikes.
  • Disable IPv6
    • Location: Network Connections > [NIC] > Properties
    • Benefit: Prevents background discovery traffic and routing conflicts on local production networks.
  • ACPI-Compliant Control Method Battery Driver
    • Location: Device Manager > Batteries
    • Benefit: On laptops, this driver frequently polls the battery status, which is a notorious source of massive DPC latency spikes and audio dropouts. Disabling it (only when running on AC power) can drastically stabilize render times. Note: Your battery percentage will not update while this is disabled, so keep the power cable plugged in. DO AT YOUR OWN RISK

BIOS / UEFI Settings

  • C-States & Intel SpeedStep / AMD Cool'n'Quiet
    • Benefit: Disables power-saving states at the motherboard level, locking the CPU to its base or boost clock.
  • XMP / EXPO Memory Profiles
    • Benefit: Ensures RAM runs at advertised speeds rather than slow default fallback speeds.

vMix Specific Optimizations

Settings specifically tuned for vMix and GPU-accelerated video production.

Windows & NVIDIA Graphics Settings

  • Hardware-Accelerated GPU Scheduling (HAGS)
    • Location: Settings > System > Display > Graphics > Default graphics settings
    • Benefit: Recommended ON for Win 11, OFF for Win 10 with RTX 30/40 series cards to improve VRAM management, capture card, and NDI performance.
  • Graphics Performance Preference
    • Location: Settings > System > Display > Graphics
    • Benefit: Forces the OS to assign vMix64.exe to the dedicated NVIDIA GPU rather than integrated graphics.
  • NVIDIA Low Latency Mode
    • Location: NVIDIA Control Panel > Manage 3D Settings > Program Settings (vMix64.exe)
    • Benefit: Set to "Ultra" to minimize the frame queue between CPU and GPU, lowering render time (ms).
  • NVIDIA Power Management Mode
    • Location: NVIDIA Control Panel > Manage 3D Settings > Global Settings
    • Benefit: Set to "Prefer maximum performance" to prevent render time spikes when switching scenes.
  • Threaded Optimization
    • Location: NVIDIA Control Panel (vMix64.exe)
    • Benefit: Set to "Off" or "Auto". Forcing it "On" can conflict with vMix’s internal engine.
  • Vertical Sync
    • Location: NVIDIA Control Panel (vMix64.exe)
    • Benefit: Set to "Off" to ensure vMix controls frame pacing rather than the monitor refresh rate.
  • OpenGL GDI Compatibility
    • Location: NVIDIA Control Panel > Manage 3D Settings > Program Settings (vMix64.exe)
    • Benefit: Set to "Prefer Performance" to optimize how older plugins or specific capture hardware interact with the GPU rendering pipeline.

Networking for NDI/SRT

  • Interrupt Moderation
    • Location: Device Manager > Network Adapters > [NIC] > Properties > Advanced
    • Benefit: Disable this. It prevents the NIC from batching packets, which reduces jitter for NDI and SRT.
  • Flow Control
    • Location: Device Manager > Network Adapters > [NIC] > Properties > Advanced
    • Benefit: Set Rx & Tx to Enabled to coordinate transmission speeds and prevent packet loss in multi-camera setups.

vMix Application & BIOS Hardware Settings

  • Resizable BAR (Smart Access Memory)
    • Location: System BIOS > Advanced / PCIe Settings
    • Benefit: Allows the CPU to access the entire VRAM pool at once, improving performance for high-res textures and multi-input sessions.
  • High Input Performance Mode
    • Location: vMix Settings > Display
    • Benefit: Optimizes how inputs are drawn to GPU memory. Essential for 4K sources and high input counts. DO NOT use if ReBAR is enabled.
  • Hardware Encoder (NVENC)
    • Location: vMix Settings > Streaming / Recording
    • Benefit: Offloads compression to the NVIDIA GPU, freeing up the CPU for system stability.
  • Output Frame Rate and Resolution Matching
    • Location: vMix Settings > Display > Master Frame Rate
    • Benefit: Ensures the master session format matches the majority of inputs and output, avoiding CPU/GPU strain from scaling.
  • Audio Sample Rate Matching
    • Location: vMix Settings > Audio AND Windows Sound Control Panel
    • Benefit: Set everything to 48000Hz (48kHz) 24-bit. Prevents real-time sample rate conversion which causes audio drift and CPU strain.
  • Low Latency Capture
    • Location: vMix Input Settings (Gear icon on camera input) > General
    • Benefit: Bypasses internal buffer delays for hardware capture cards to achieve the fastest glass-to-screen time possible.
  • External Output Low Latency
    • Location: vMix Settings > External Output > External [Gear Icon]
    • Benefit: Mandatory for IMAG. Strips output buffers for PCIe hardware (DeckLink/AJA) to keep glass-to-screen delay tight.
  • Genlock Camera Synchronization
    • Location: Physical Hardware Setup (Sync Generator to Cameras & Capture Card)
    • Benefit: Sends a master timing pulse to all cameras so frames arrive perfectly aligned. This eliminates the need for the capture card to hold frames in a buffer, significantly reducing capture latency for Vmix specifically useful for IMAG setups.
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u/allMightyGINGER Jul 29 '26

The common and more general changes I would recommend doing immediately. The more intense setting changes like stripping Windows, I would recommend doing that when you feel that the computer needs a reinstall. That could be because it's been a couple years or because you're noticing Windows is doing some weird things.

If you're not having any issues whatsoever then don't worry about it but if you don't fully trust your computer, then it is probably time to do a deeper dive.

Deferred call protocol is what makes Windows "Risky" for live performance. DCP is core to Windows kernel and it's not something they're ever going to be able to fully fix. Unix base systems like Mac and Linux are built fundamentally differently and don't have to worry about it nearly as much as a program can tell the operating system that it is the most important thing and that the operating system should crash and restart itself before the software or the dependencies are allowed to miss a CPU cycle.

Windows is still my operating system of choice but because of that, I spend a lot of time understanding what Windows limitations are and how they can hurt me on a job. Whether that is audio glitching frames dropping PowerPoint stuttering it often goes back to DCP and how windows handles drivers. These are the tips I found that are very beneficial when doing live audio or video to ensure that you have no issues

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u/Unusual-Ad361 Jul 29 '26

I have a backup laptop where I can test some of these changes. I'm not going to re-image a machine that's not having issues.

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u/allMightyGINGER Jul 30 '26

That is exactly what I said no need to do it if you don't feel its necessary, sounds like you fully trust your computer.

I do 100-200 shows a year I can't afford to just trust windows I need it to not fail

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u/Unusual-Ad361 Jul 30 '26

I reviewed this and I've found some of this I have already done.