How the Rigorous GPU Tests Work
A fast graphics card can run a simple test at your monitor’s refresh rate and look idle. The rigorous tests fix that by adding load until your GPU is actually working hard, and by checking its results as well as its speed. This page explains how each part works.
Rigorous Stress Suite
This canvas shows the animated graphics workload used to stress the GPU. It is decorative; results are listed in the metrics below.
- FPS
- –
- 1% LOW
- –
- FRAME TIME
- –
- SCORE
- –
- TIME
- 0:00
- LOAD
- –
- ERRORS
- 0
Before you start
GPU stress tests can significantly increase GPU load, temperature, power draw and fan speed.
Stop the test if your system becomes unstable, overheats, crashes or behaves unexpectedly. Do not run extreme tests on hardware with known cooling problems. This website cannot guarantee hardware safety.
This is a deliberately punishing test. It can push your GPU to its thermal and power limits for minutes.
- Laptops: plug in the charger and make sure the vents are clear.
- Make sure your GPU is cooled properly. Do not run this with known fan or cooling problems.
- Save your work and close other important tabs. A weak or overheated GPU can make the screen flicker or the graphics driver reset, which may close apps.
- You can stop at any time with the Stop button or the Escape key. The test also stops itself if frames take more than two seconds.
Long run: this test keeps the GPU busy for five minutes or more, so your computer will get warm. Laptops should be plugged in. You can stop at any time with the Stop button.
About this tool
Load stacking and Torture
Instead of changing the picture, we draw the same work several times per frame. Torture is Extreme with eight stacked passes, so each frame costs about eight times as much. Torture starts gently (1, 2, 4 then 8 passes) and measures a few frames first, so a weak GPU is given fewer passes instead of freezing the tab.
The limit finder
The finder raises the load in steps (x1, x2, x3, x4, x6, x8, x12, x16, x24, x32 and on) for five seconds each. It stops when sustained FPS falls below 60% of your refresh rate, never below 30 FPS, then holds the last step that kept up. You get the highest sustainable step, the GPU time per frame (from a hardware timer when the browser offers one, otherwise from wall-clock time below vsync) and a Limit Score.
The Limit Score uses the same formula as other scores with the load step as a factor, so it is not capped by your refresh rate.
Error detection
The integrity test runs a calculation whose exact answer is known and compares samples with the first pass and a CPU reference, then verifies memory patterns. Errors are counted with timestamps. It is detect-only: it reports what it measured and does not diagnose a cause.
The rigorous suite
The suite runs six phases in 5, 10 or 15 minutes: shader load, memory bandwidth, geometry, integrity, limit finder, and a repeat of the first phase. It ends FAIL on any error, driver reset or lost context, or a drop of more than 15% from the first phase to the last. A smaller drop, or a run that was reduced or stopped early, is a WARNING. Otherwise it is PASS.
How to read the results
Each rigorous test ends with a plain-language result. Pass means no errors were seen at the tested load. A limit result shows the highest load the browser handled before frames fell below target. An integrity failure means the calculation gave a different answer, which is a stronger signal than a low score. Open the stability test page for the details of each.
Built-in safety
Torture and the suite need a tick on an acknowledgement box. A Stop button is always visible. If two frames in a row take more than two seconds the test aborts and says so. The default intensity stays Medium.
What a browser cannot measure
We cannot see GPU temperature, clock speed or power draw, and WebGL cannot exercise tensor cores or ray-tracing units. A suite that passes tells you the GPU gave correct results and held its speed in these workloads, nothing more.
Frequently asked questions
Why does a drop between the first and last phase matter?
The suite repeats the first workload at the end. A large fall in FPS between the two can mean the GPU slowed down under heat or power limits, though we cannot see which.
Why is my Limit Score not capped at 60 FPS?
Because the finder keeps adding load. A faster GPU holds a higher step, which raises the score.
Are the rigorous tests safe?
They are heavier than the normal tests, so they ask for confirmation and always show a Stop button. Close other work first.
Which one should I run first?
Start with the integrity check. If it passes, try the limit finder to see how much headroom you have.
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