http://programmer.ie/tags/num_workers/ Recent content in Num_workers on Programmer.ie: Modern AI programming Hugo en-us Sat, 08 Aug 2026 13:21:00 +0100 http://programmer.ie/post/pytorch-zero-to-hero-05/ Sat, 08 Aug 2026 13:21:00 +0100 http://programmer.ie/post/pytorch-zero-to-hero-05/ <h2 id="pytorch-zero-to-hero--step-05">PyTorch: Zero to Hero — Step 05</h2> <p>A fast model with a slow input pipeline is still a slow training system.</p> <p>One of the most common PyTorch performance failures looks like this:</p> <div class="highlight"><pre tabindex="0" style="color:#f8f8f2;background-color:#272822;-moz-tab-size:4;-o-tab-size:4;tab-size:4;"><code class="language-text" data-lang="text"><span style="display:flex;"><span>GPU utilization: 20% → 95% → 10% → 90% → 15% </span></span></code></pre></div><p>The model is not necessarily slow.</p> <p>The GPU may simply be waiting for the next batch.</p> <p>This article is about finding out <strong>where the wait is happening</strong>.</p>