Why Amazon Ec2 Is As Slow As My Machine When Running Python Code?

I'm using g2.2 xlarge instance of amazon. I'm having this function that takes 3 minutes to run on my laptop which is so slow. However, when running it on EC2 it takes the

Solution 1:

I think you need to profile your code locally and ensure it really is CPU bound. Could it be that time is spent on the network or accessing disk (e.g. reading the image to start with).

If it is CPU bound then explore how to exploit all the cores available (and 25% sounds suspicious - is it maxing out one core?). Python can be hard to parallelise due to the (in)famous GIL. However, only worry about this when you can prove it's a problem, profile first!