Spot vs. On-Demand Instances: What's the Difference on Runpod?

Spot and on-demand instances are two types of AWS EC2 instances that cater to different needs based on cost and reliability. Spot instances allow users to access spare compute capacity at significantly reduced costs, often around 50% cheaper than on-demand instances, but they come with the risk of being interrupted without notice if the capacity is required elsewhere. This makes spot instances ideal for workloads that are stateless or have built-in checkpointing, such as training algorithms that can resume from the latest checkpoint if interrupted. On the other hand, on-demand instances offer non-interruptible compute capacity, making them suitable for interactive workloads or tasks where uninterrupted operation is essential, such as working in a Jupyter notebook. The choice between the two depends on the user's need for cost efficiency versus the assurance of continuous operation.