Skip to content

gpu_time_ms

Jump to bottom
killown edited this page Mar 16, 2026 · 1 revision

Metric: gpu time ms (Execution Time)

Executive Summary

gpu time ms measures the actual duration the GPU spent processing the rendering commands for a single frame. This represents the "Brawn" of your system, the time taken to calculate shaders, rasterize triangles, and draw the cubes to the buffer.

  • Lower is better: High GPU efficiency leaves more slack ms for the presentation deadline.
  • The Load Indicator: As you increase the number of cubes or the resolution, this is the number that will climb.

Why this number matters

This is the definitive metric for GPU Bottlenecking. It tells you if your performance limits are caused by the graphics hardware or the code driving it.

  1. True Workload: Unlike FPS, gpu time ms isn't affected by VSync or CPU stalls. It measures the raw effort required to render your scene.
  2. Thermal & Power: If this number is consistently high, your GPU is running at full utilization, which will eventually lead to thermal throttling or power-limit drops.

How to read the numbers

GPU Time State Action
< 4.0 ms Underutilized You have massive headroom. Add more cubes or higher quality effects.
5.0 - 7.0 ms Efficient Ideal for 120Hz/144Hz targets. Good balance of speed and fidelity.
> 8.33 ms Budget Break You can no longer sustain 120 FPS. Performance will drop to 60 FPS or lower.
> 16.6 ms Overloaded You are now below 60 FPS. Immediate optimization is required.

GPU Time vs. CPU Frame Time

  • CPU Frame Time is how long it took to write the instructions.
  • GPU Time is how long it took to follow them.

If cpu frame ms is 1ms but gpu time ms is 15ms, you are GPU Bound. Your code is efficient, but your graphics hardware is drowning. You need to lower settings, simplify shaders, or reduce the vertex count.

Troubleshooting

  • Stable High Value: Your shaders are too complex or you are drawing too many objects. Use instancing or reduce the resolution.
  • Sudden Spikes: Often caused by "Shader Compilation" or large textures being swapped into GPU memory.
  • Lower than Delta ms: This is normal. The "gap" between gpu time ms and delta ms is where your CPU work and slack ms live.

The Goal

For high-refresh gaming, the goal is to keep gpu time ms at approximately 60% to 70% of your ideal ms. This provides enough "buffer" to prevent a single complex frame from causing a VSync miss and a spike in missed frames.

Clone this wiki locally