Rendering, benchmark and hardware requirements

How Mutant assembles the final video

Rendering is the final step where Mutant stitches all the pieces of a video (footage, voiceover, subtitles) into a finished file. Under the hood it uses ffmpeg version 6.0 — installed automatically, nothing to download separately.

The speed of this step depends most on which encoder builds the video. So you don't have to figure that out by hand, Mutant picks the encoder for you — via a built-in benchmark.

Rendering is part of the larger pipeline. To see how a video moves through every step from idea to finished file, read How the pipeline works.

What the encoder benchmark is

On first launch (and after a GPU change) Mutant runs a short test — a 20-second render — and measures which encoder is fastest on your machine.

It checks a ladder, top to bottom, stopping at the first one that works:

1. NVENC — hardware encoder on Nvidia GPUs
2. QSV — hardware encoder on Intel CPUs
3. AMF — hardware encoder on AMD GPUs
4. CPU (libx264) — software encoding on the processor

The first three use a dedicated chip on the GPU or CPU and are several times faster. CPU works everywhere but is slow — a fallback for when no hardware encoder is available.

The result is cached: the benchmark doesn't run every time; Mutant remembers the choice and reuses it for all following renders.

How to read the result in Setup

Open the Setup tab → the "Render: encoder and benchmark" section. There you'll see:

• which encoder is currently selected;
• a render-time estimate — for example, "a 50-minute video ≈ N minutes". This tells you roughly how long a typical video will take on your hardware;
• buttons to re-run the test or choose the encoder manually.

If the estimate looks reasonable and the encoder is a hardware one (NVENC/QSV/AMF), you're all set — nothing to do.

When to re-run the benchmark

Most of the time — never; the cache handles it. Re-run when your hardware changes:

• you changed or added a GPU — Mutant notices and offers to re-run the test;
• you updated your GPU driver — worth re-checking;
• the encoder is CPU even though your PC has a suitable GPU (see below).

You can re-run the test manually from the button in the same Setup section.

Choosing the encoder manually

Auto-selection is usually best, because it's based on a real speed measurement. But in the "Render: encoder and benchmark" section you can set the encoder by hand — for example, to force a specific option.

Tip: if a manual choice misbehaves (the render fails or runs too slowly), just re-run the benchmark and Mutant will pick a working encoder automatically again.

What to do if rendering is slow

A slow render almost always means one thing: the CPU encoder was selected because no hardware one was found. What you can do:

• Check the encoder in Setup. If it says CPU, then NVENC/QSV/AMF aren't available.
• Update your GPU driver and re-run the benchmark — a hardware encoder sometimes hides behind an old driver.
• Make sure you actually have a GPU with a hardware encoder. Rendering on CPU still works and gives the same result — it just takes longer.

A hardware encoder (NVENC/QSV/AMF) speeds up rendering several times over. If you plan to produce content at volume, a GPU with one saves a lot of time.

Hardware requirements

For Mutant to run smoothly:

• Windows 10 or 11, 64-bit
• Internet — for the app to work
• Free disk space for video — finished files take up noticeable space
• ~2 GB for the runtime — this includes ffmpeg and the other components installed automatically

A hardware encoder (Nvidia/Intel/AMD) isn't required, but noticeably speeds up rendering.

Full requirements and download on the Download page.