Original article was published on Artificial Intelligence on Medium
This is actually an incorrect statement. More RAM does not make training faster. What RAM allows you is to either (1) use bigger models or (2) double the batch-size. Among these, (2) can actually give you better performance if and only if your GPU is not reaching its maximum occupancy.
For a better comparison, you should have tuned both Colabs to the maximum batch-size their GPUs can fit. Thus, trying to raise its occupancy to the maximum. Then, I suspect you would see a major improvement for the paid Colab.
You can also rely on nvidia command line tools to probe the current occupancy / GPU-use, but I am not sure if you can do that from Colab.
Apart from that, great article. I myself was unaware that Colab had a paid version.