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Best Subnautica 2 settings for the Steam Deck (RDNA2 iGPU) (2026)

On a Steam Deck (RDNA2 iGPU) (paired with a balanced Intel Core i5-8600K-class CPU), Subnautica 2 runs at roughly 61 FPS at 1080p with our optimized settings — up from about 28FPS with everything maxed. Here's the configuration and what each setting costs.

The Steam Deck (RDNA2 iGPU) is a handheld graphics card with 4GB of VRAM, and Subnautica 2 is a moderately demanding game. Paired with the Intel Core i5-8600K, it runs well at 1080p — about 61 FPSwith FrameCoach's optimized settings, a clear jump from roughly 28 FPS with everything on High.

Across resolutions you can expect around 61 FPS at 1080p and 46 FPS at 1440p, dropping to roughly 26 FPS at 4K. The biggest free win is FSR upscaling — set it to Quality for a large FPS boost at little visual cost.

ResolutionAll-High FPSOptimized FPS
1080p2861
1440p1746
4K1026
💡 Subnautica 2: Early-access Unreal Engine 5 - Lumen Global Illumination is the heaviest setting; upscaling helps a lot.
🚀 Biggest free win: enable FSR (Balanced) — about +55% FPS for a small sharpness trade.
Recommended settings
Upscaling — FSRBalanced+55% FPS
Subnautica 2 is built on Unreal Engine 5 and supports upscaling. Enable it first for a big, low-cost FPS gain.
Global Illumination (Lumen)Low+18% FPS
UE5 Lumen lighting — the single heaviest setting underwater. Medium is a big saving over Epic with little visible difference in murky depths.
Flora / Foliage DensityLow+7% FPS
Density of coral and plant life. Lower it for steadier FPS in dense reefs.
View / Detail DistanceMedium+5% FPS
How far terrain and props render. Lower it a notch first if you dip in open water.
Shadow QualityMedium+4% FPS
Shadow resolution and range. High is a strong step down from Epic.
Water & Caustics QualityMediumbaseline
The shimmering light patterns and water detail that define the look. Medium keeps the vibe while saving frames.
Effects QualityMediumbaseline
Particles, bubbles and volumetrics. Medium is plenty.
Texture QualityHighbaseline
Surface detail — cheap on FPS if it fits your VRAM.

⚡ Fine-tune this for your exact CPU & target FPS →

🎯 Can the Steam Deck (RDNA2 iGPU) run Subnautica 2? See the verdict →

Subnautica 2 on other GPUs
Other games on the Steam Deck (RDNA2 iGPU)
Frequently asked

What FPS does the Steam Deck (RDNA2 iGPU) get in Subnautica 2?

With FrameCoach's optimized balanced settings, the Steam Deck (RDNA2 iGPU) averages around 61 FPS at 1080p in Subnautica 2 — up from about 28 FPS with everything on High.

Can the Steam Deck (RDNA2 iGPU) run Subnautica 2 at 1440p?

At 1440p with optimized settings, the Steam Deck (RDNA2 iGPU) averages roughly 46 FPS in Subnautica 2; turn on upscaling or aim for a locked 60 for the best feel.

What are the best Subnautica 2 settings for the Steam Deck (RDNA2 iGPU)?

Turn on FSR (Balanced), keep ray tracing off for maximum FPS, and ease the heaviest options like Global Illumination (Lumen) and Flora / Foliage Density down a notch. The full per-setting breakdown is above.

FPS figures are estimates from a generalized model (hardware tier × game load × per-setting weights), not live benchmarks — real performance varies by scene, drivers and game version.