STAGE 2 OF 3

GPU Compute Stress Test

Stage 2 puts the GPU under 60 seconds of sustained compute shader load. It renders a 3D scene using complex multi-pass shaders that saturate GPU compute units, L2 cache, and VRAM bandwidth simultaneously. Like the CPU stage, the diagnostic signal is decay — how much performance falls from the initial peak as the GPU's thermal throttle engages.

What is Measured

PEAK FPS

Burst ceiling

VALLEY FPS

Thermal floor

DECAY %

Throttle depth

VRAM PRESSURE

Memory stress

VRAM Pressure Levels

LOW
Headroom available

MODERATE
Near capacity

HIGH
Bandwidth limited

CRITICAL
Compression active

VRAM pressure indicates how close the workload pushes GPU memory to its bandwidth ceiling. Critical VRAM pressure typically causes the driver to engage lossy texture compression, producing frame time spikes visible as high decay even on thermally healthy cards.

How the Test Works

The benchmark renders a 3D scene via WebGL 2.0 compute shaders for the full 60-second duration. FPS is sampled every frame. Peak is captured in the first 5 seconds before thermals stabilize; valley is the lowest sustained FPS over a 3-second rolling window. Decay is (peak − valley) / peak × 100.

The stage runs automatically after the CPU cooldown. When it completes, a 1-second cooldown overlay plays before advancing to Stage 3.

Scoring Thresholds (GPU Decay)

S grade: Decay ≤3% — GPU maintains peak clocks throughout, excellent VRM and cooling
A grade: Decay ≤8% — minimal power/thermal headroom loss
B grade: Decay ≤15% — moderate throttle; check fan curve and case airflow
C grade: Decay ≤25% — significant throttle; verify GPU fan speed and heat pipe contact
D grade: Decay >25% — severe GPU thermal throttle; investigate cooling immediately

Common Causes of High GPU Decay

Passive or conservative fan curve (card runs hot before fans spin up)
Dried thermal paste on GPU die (particularly on cards 3+ years old)
Restricted airflow inside case (GPU exhausting into blocked rear panel)
Aggressive power limit in driver or GPU BIOS
High ambient temperature or insufficient room cooling

Next Stage

After Stage 2 completes, the test automatically advances to Stage 3 — Path Tracing Engine.