Frame Budget at 120 FPS: What We Cut and What It Bought

Engineering a real-time Vulkan presentation pipeline to hit 8.33 ms at 4K native without resolution scaling.

Core Finding:Most modern game pipelines rely on temporal upscalers and dynamic resolution scaling to mask render budget deficits. In Atlas Engine, our standing mandate targets 120 fps (8.33 ms frame budget) at 3840x2160 native with zero upscaling. Here is the telemetry on how we profiled our compute and draw queues to hold 2.51 ms of honest GPU/staging work.

Honest GPU Compute

2.51 ms

GPU staging (0.252 ms) + physics (1.698 ms) + cloth (0.555 ms); 30.1% of the 8.33 ms 120 fps ceiling.

GPU Pass Timings

1.90 ms

Hardware timestamp queries: shadow pass 0.49 ms, main scene pass 1.41 ms.

Descriptor Headroom

3,691 / 8,192

3,691 mesh primitives drawn per frame against the 8,192 descriptor-set allocation cap.

Cloth Optimization

111x-342x

Cloth LUT lookup (1.6 µs/garment) replaces live PBD solve (548 µs/garment), saving 21.7 ms across 40 NPCs.

Empirical Findings Table

Per-frame compute and presentation breakdown at 3840x2160 native

Telemetry Metric	Measured Value	Context & Observability
Honest GPU Compute	2.51 ms	GPU staging (0.252 ms) + physics (1.698 ms) + cloth (0.555 ms); 30.1% of the 8.33 ms 120 fps ceiling.
GPU Pass Timings	1.90 ms	Hardware timestamp queries: shadow pass 0.49 ms, main scene pass 1.41 ms.
Descriptor Headroom	3,691 / 8,192	3,691 mesh primitives drawn per frame against the 8,192 descriptor-set allocation cap.
Cloth Optimization	111x-342x	Cloth LUT lookup (1.6 µs/garment) replaces live PBD solve (548 µs/garment), saving 21.7 ms across 40 NPCs.

Engineering Action Directives

Targeting 120 FPS (8.33 ms) natively enforces architectural discipline across GPU compute queues that 60 FPS targets often obscure.
Precomputed lookup tables for complex physical simulations like garment physics offer dramatic throughput gains over per-frame iterative solvers.

Methodology Boundaries & Limits

Single hardware platform: Benchmarked on an AMD Ryzen 7 9800X3D and NVIDIA RTX 5080; results will vary across lower-tier hardware and mobile GPUs.
Static mesh asset set: Evaluated on specific island scene geometry and NPC crowd counts; dynamic scene streaming may introduce additional frame pacing variance.