I did some comparisons on Colab vs local 3090 in another thread. Here’s a link (Colab model learning speed - #2 by matdmiller) if you’re interested. Colab performance varied greatly depending on if you get assigned a K80 vs T4. The OP was trying to figure out why his Colab performance varied significantly from day to day. I am running locally on Ubuntu 18.04 w/ Docker for fast.ai on a machine I built about 5 years ago and recently upgraded w/ a 3090.