Minimum CPU Requirements for rav1e AV1 Encoding

Encoding video with the rav1e AV1 encoder (librav1e) requires a modern processor with specific instruction sets to achieve acceptable speeds. This article details the absolute minimum CPU specifications, recommended hardware for optimal performance, and how instruction sets like AVX2 impact your encoding times.

The Baseline: Hardware Instruction Sets

To run librav1e at any acceptable speed, your CPU must support AVX2 (Advanced Vector Extensions 2). The rav1e encoder relies heavily on assembly-level optimizations written specifically for AVX2 and AVX-512.

Running librav1e on an older CPU without AVX2 (such as Intel Nehalem or older AMD chips) will result in extremely slow encoding speeds, often dropping below 1 frame per second (FPS).

Minimum CPU for Acceptable Speeds (1080p Encoding)

For encoding 1080p video at “acceptable” speeds—defined as 15 to 30 FPS using medium-speed presets (Speed 5 to 7)—you need the following minimum hardware:

• AMD: Ryzen 5 3600 (6 Cores / 12 Threads) or newer.
• Intel: Core i5-10400 (6 Cores / 12 Threads) or newer.
• Apple Silicon: Apple M1 chip or newer.

Processors with fewer than 6 cores will struggle to multi-thread the encoding process efficiently, leading to bottlenecking.

Recommended CPU for High-Performance Encoding

If you plan to encode 1080p video faster than real-time, or if you are working with 4K source files, the recommended CPU tier increases:

• AMD: Ryzen 7 5700X / Ryzen 5 7600X (8 Cores / 16 Threads) or higher.
• Intel: Core i7-12700K (12 Cores / 20 Threads) or newer.

These CPUs feature superior single-core performance and support AVX2/AVX-512, which rav1e utilizes to accelerate the mathematical calculations required for AV1 spatial and temporal predictions.

How rav1e Speed Presets Affect CPU Requirements

The speed of librav1e is highly dependent on the “Speed” parameter, which ranges from 0 (slowest, highest quality) to 10 (fastest, lowest quality):

• Speeds 0–4: Highly resource-intensive. Even high-end 16-core CPUs will struggle to exceed 5 FPS.
• Speeds 5–7: The sweet spot for balance. Mid-range 6-core and 8-core CPUs can achieve acceptable encoding speeds (15–40 FPS).
• Speeds 8–10: Fast encoding. Suitable for real-time streaming or quick drafts, achievable on budget 4-core CPUs with AVX2.