How to Optimize Davinci Fusion for Performance

Quick Answer

To optimise DaVinci Resolve's Fusion page for performance, adjust proxy settings, manage node complexity, use optimised media, and leverage GPU acceleration correctly. On mid-range systems, these steps can dramatically reduce render times and preview lag.

GPU and Memory Settings for Fusion

Fusion is heavily GPU-accelerated, so starting in Preferences is essential. Navigate to DaVinci Resolve Preferences, then the Memory and GPU tab. Set GPU processing mode to CUDA (NVIDIA) or OpenCL (AMD) rather than Auto - Auto sometimes selects the wrong device on multi-GPU systems or laptops with discrete and integrated graphics. Allocate at least 70% of available system RAM to Resolve. On a system with 32GB RAM, setting Resolve's allocation to 22-24GB prevents excessive caching to disk. For SA users with slower HDDs for secondary storage, keeping Fusion's cache in RAM rather than on disk is a significant speed boost.

Node Graph Optimisation and Proxy Workflow

Fusion node graphs compound quickly. Each blur, colour correction, and merge node adds GPU overhead. Use Proxy mode (press Shift+P in Fusion) when building complex node trees - this renders at a fraction of resolution for real-time preview and switches to full resolution only for final export. Disable viewer LUT transforms in the Fusion viewer when not needed, as these add a processing step to every frame preview. Group frequently used node chains using Macro nodes to reduce the visual complexity of the graph and improve navigation speed on large projects.

Optimised Media and Cache Strategy

Importing raw camera footage directly into Fusion is the slowest approach. Use the Generate Optimised Media function in the Cut or Edit page first: right-click clips and select Generate Optimised Media in DNxHR SQ or ProRes Proxy format. Fusion will then read these lightweight proxies instead of decoding raw 4K or 6K files frame by frame. Enable background caching in Fusion preferences so that Fusion pre-renders node outputs in the background while you work. This is especially useful for SA editors who step away during loadshedding breaks and return to a pre-rendered timeline.

Frequently Asked Questions

Why is DaVinci Fusion so slow on my PC? Fusion lag is usually caused by GPU processing mode being set incorrectly, insufficient RAM allocation, or using raw high-resolution media instead of optimised proxies. Check all three before adding hardware.

Does Fusion use the GPU or CPU for rendering? Fusion primarily uses the GPU. Ensure GPU acceleration is enabled in Resolve preferences and that your discrete GPU (not integrated) is selected as the processing device.

How do I reduce preview lag in Fusion? Enable Proxy mode with Shift+P, use optimised media for your source clips, and ensure background caching is enabled. These three steps resolve the majority of Fusion preview performance issues.