<p>Suppose, in a Kajiya style path tracing algorithm, I have <code>100x100</code> pixels, and I am using <code>32 samples per pixel</code>. So, the total number of samples <code>is 320000</code>.</p>
<p>Now, if I render the same scene with <code>25x25</code> pixels (I meant, then upscale it to <code>100x100</code> resolution), and use <code>8 samples per pixel</code>, the total samples are <code>5000</code>.</p>
<p>From these two, can I theoretically estimate that my new path tracing can be <code>(320000/5000) = 64 times</code> faster?</p>
<p>How to calculate the theoretical performance gain in path tracing? Would appreciate any suggestions.</p>

<pathtracing><performance><importance-sampling><supersampling>
Theoretical speedup from sample number in path tracing algorithm
bim
# Theoretical speedup from sample number in path tracing algorithm

(Asked by: username_0 on 2023-06-13)

Suppose, in a Kajiya style path tracing algorithm, I have `100x100` pixels, and I am using `32 samples per pixel`. So, the total number of samples `is 320000`.

Now, if I render the same scene with `25x25` pixels (I meant, then upscale it to `100x100` resolution), and use `8 samples per pixel`, the total samples are `5000`.

From these two, can I theoretically estimate that my new path tracing can be `(320000/5000) = 64 times` faster?

How to calculate the theoretical performance gain in path tracing? Would appreciate any suggestions.

**Tags:** pathtracing, performance, importance-sampling, supersampling

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## 0 answers

