Dehancer
Dehancer performance tips

1. Why is Dehancer demanding of computational resources?

Dehancer is one of the most advanced and sophisticated film emulation tools out there today. We managed to authentically reproduce most of the effects that occur in film emulsion, but this required complex algorithms and, accordingly, high computing power.

Dehancer includes relatively “lightweight” tools – Input, Film, Expand, Print, Color Head, Vignette, Film Breath, Gate Weave and False Color. When using them, even on older computers ( 5-7 years old), you can easily achieve real-time playback, at least in FullHD resolution.

However, among the Dehancer tools there are also “heavier” effects – Film Grain, Halation, Bloom. They require a lot of computation and can reduce significantly performance. These tools use non-linear operations, sophisticated analysis, finding light sources and contrast edges, working with transformations in the spatial domain, and even completely rebuilding an image from scratch (in the case of grain). This requires a powerful GPU and a large amount of video memory to store all the textures involved in the processing.

These algorithms make it possible to achieve the credibility that makes Dehancer a unique tool.

Dehancer is not the only and far from the slowest video processing tool on the market. For example, intelligent noise reduction tool NeatVideo does not work in real time, and, apparently, it was never expected. Whereas, the Dehancer Grain tool uses similar calculations, but provides reasonably higher performance.

2. What kind of computer does one need for Dehancer?

To work comfortably with the plug-in, you need a fast, modern computer with a good graphic card and sufficient video memory.

 of Dehancer system requirements.

According to our observations, with the top-end configurations of NVIDIA GeForce RTX 3080 graphic cards, the plug-in works perfectly near real time up to Ultra HD resolution. Similar performance is achieved on Apple Silicon M1 Pro and M1 Max processors.

To make it easier to evaluate performance on different configurations and to help you plan your system upgrade, we have released a special benchmark. With its help, everyone can evaluate the speed of the plug-in on their computer and compare it with the results on various configurations.

3. Essential Workflow Considerations

  • Professional colourists working in DaVinci Resolve, particularly with 4K and higher resolutions, typically avoid full-resolution real-time playback.
  • The optimal approach involves temporarily reducing timeline resolution (e.g., to Full HD) or utilising Playback Proxy, Render Cache, or Optimised Media. This maintains final render quality whilst dramatically improving colour correction workspace responsiveness.
  • For occasional 4K quality checks, resolution or proxy settings can be toggled as needed.

4. Estimated GPU memory consumption:

  • FullHD – 4GB minimum / 8GB recommended
  • 4K – 8GB / 12GB
  • 6K – 12GB / 16GB
  • 8K – 16GB / 24GB

5. Multi-GPU vs Single Powerful Card: The Verdict

While DaVinci Resolve can effectively utilise multiple identical GPUs, there are important caveats:

  • Mixing cards of different generations and performance levels often yields suboptimal results due to load-balancing challenges.
  • Memory parity between cards is crucial, as Resolve scales GPU memory usage to match the lowest common denominator.
  • For 4K workflows, a single top-tier modern GPU (RTX 4090 or better) typically outperforms multiple older cards. For demanding 4K+ material, dual identical high-performance cards might be considered, though budget comparisons with single-card solutions are essential.

6. Video Memory Considerations

  • Plugins handling LUTs, grain, halation, bloom, and film texture emulation (Dehancer's speciality) demand substantial video memory. Projects with high bit depth (10-12 bit) and multiple nodes may require 16GB+ per card.
  • However, large VRAM capacity alone doesn't guarantee speed - a 48GB A6000 might not outperform a faster 24GB RTX 4090 in real-world applications.

7. CPU and RAM Requirements

While Dehancer and most Resolve effects are GPU-intensive, other factors matter:

  • A reasonably powerful CPU from a current generation with good multi-threading capabilities prevents bottlenecks.
  • 32-64GB RAM is recommended for 4K RAW workflows, with some formats (RED, ARRI) potentially requiring more.
  • NVMe SSDs for cache, proxy, and source material significantly enhance system responsiveness.

8. What to do and how to improve the performance?

If you have already exhausted the possibilities for upgrading the system, then this question is more philosophical than technical. There have been periods in the history of human-machine relationships when advanced algorithms outpaced hardware technology. For example, in the early 2000s, not every home computer could play FullHD video in realtime, but today we can easily edit movies on a smartphone.

The Dehancer case is similar, but not that serious. It will take only 2-3 years for the hardware to catch up with the software part, and it will be possible to work with high FPS on relatively inexpensive configurations. Hopefully, we will be able to improve the speed at least a little in every plug-in update.

9. Optimising Dehancer: Essential Tips

  1. Turn off some non-critical effects at different stages of color grading. For example, Grain and Halation may be activated only at the final stage of video processing.
  2. Enable Proxy Mode to increase FPS by 2 or even 4 times. You can also lower the project resolution to FullHD while grading, and return to full size when rendering.
  3. Use the Optimized Media and Render Cache to play the already graded clips in real time.
  4. Convert the original video to a format that is easier to decode, for example, DNxHR or Apple ProRes, which is processed with a dedicated hardware codec on modern Apple computers and creates almost no additional processing load.
  5. If your project uses additional nodes with masks or Qualifier, they may consume a lot of extra memory and computing power. If this is the case, you can render such clips to the cache or use Compound Clips.
  6. From performance point of view, it is more effective to apply Dehancer node in Timeline mode, i.e. to the whole timeline rather than to individual clips. In the latter case, multiple plugins are launched, each of them consuming additional resources.
  7. Close unnecessary applications that may consume memory and actively use the processor in the background. Among others, Google Chrome, which gladly takes up any available amount of RAM.
  8. First step: Optimise workflow settings (reduce timeline resolution, enable proxy/optimised media, caching). Often this alone resolves performance issues.
  9. Budget considerations: If upgrading, prioritise a single high-performance card (RTX 4090/4090 Ti or Ada Generation professional equivalents).
  10. Multi-GPU setups: For extensive projects, consider dual identical cards (e.g., two RTX 4090s), ensuring adequate power supply, cooling, and chassis compatibility.
  11. Avoid mixing disparate cards across generations (like A6000 + RTX 4000). Such combinations typically yield minimal benefits and may introduce stability issues.
  12. Essential maintenance: Keep drivers updated and optimise OS settings (Windows 10/11, DaVinci preferences). Sometimes, simple driver updates or clean installations resolve performance issues.

💡Thus, if your goal is to achieve "pure" 4K real-time playback without proxies and cache (especially with 4.5K source material on a 4K Scope timeline @24fps), significant GPU investment is essential.

A modern high-end graphics card (or two) will provide substantially more real-world performance gains compared to older models with high "professional specifications". However, before upgrading your hardware, it's recommended to start with traditional optimization techniques such as reducing timeline resolution during color correction and utilizing proxies.