title: Google Colab: You are connected to a GPU runtime, but not utilizing the GPU
body: <p>There has been many questions on this topic before, but none of the answers fit my specific question.</p>
  <p>I am trying to train Mask RCNN using Keras 2.2.5 on Google Colab. I am getting a message saying &quot;You are connected to a GPU runtime, but not utilizing the GPU&quot;. I look up similar questions on stack overflow:</p>
  <p><a href="https://stackoverflow.com/questions/62852603/why-isnt-my-colab-notebook-using-the-gpu">Why isn&#39;t my colab notebook using the GPU?</a></p>
  <p><a href="https://stackoverflow.com/questions/61360422/anyone-experienced-the-warning-about-google-colaboratoryyou-are-connected-to-a">Anyone experienced the warning about Google colaboratory:You are connected to a GPU runtime, but not utilizing the GPU</a></p>
  <p>but all of them only say to use a package that uses GPU, such as Tensorflow. However, I am using Keras 2.2.5 (presumably with Tensorflow 1.14 backend as I had to install Tensorflow 1.14 for Keras 2.2.5 to work), which is compatible with GPU. Is there any reason why this is happening?</p>
  <p>More info:</p>
  <ul>
  <li>Google Colab</li>
  <li>Python 3.6</li>
  <li>I am using Keras 2.2.5 (with Tensorflow 1.14) instead of Keras 2.4.3 because I am using some code from 2017 which works only with Tensorflow 1. Thus, Tensorflow 2 is not possible to use.</li>
  <li>I have used Google Colab to train a GAN before, but this error never appeared. However, I used Tensorflow 2 in that situation.</li>
  <li>I have never needed to add any code to specify that a GPU should be run, and I don't know if I should do that here.</li>
  <li>I had to download Keras 2.2.5 and Tensorflow 1.14 to replace the existing versions (Keras 2.4.3 and Tensorflow 2.2) and I'm unclear if that has anything to do with it</li>
  </ul>