💰 How can I limit my compute costs?

There are several strategies you can use to manage and reduce compute usage when designing your challenge:


  • Limit the number of participants or teams
    By enabling manual participant review, you gain control over who is allowed to submit. Once you’ve reached a desired number of participants, you can stop accepting new ones.

  • Restrict the number of submissions
    Submission limits can be applied globally or within a defined window.
    A common and effective setup is to have:
    • A public debugging phase using a small test set to allow unrestricted testing
    • A final test phase with stricter limits, e.g., only one allowed submission

  • Set a maximum runtime per algorithm job
    Grand Challenge enforces time limits per single job (i.e., for each input item).
    Encouraging fast inference is not only cost-effective but also aligns with real-world clinical needs.
    ⚠️ Be cautious: overly short limits may restrict the development of complex or meaningful solutions.

  • Use a two-stage challenge design
    Run an initial qualification phase, then invite only selected participants to submit to the final test phase. This approach significantly reduces overall compute usage.

  • Reduce the size of the test set
    Fewer test cases directly reduce costs. However, this comes at the expense of statistical power and robustness of the evaluation.

  • Batch your inputs when appropriate
    If your dataset contains many small input items (e.g., small patches or slices), consider batching them into a single input per algorithm job.
    ⚠️ Downsides:
    • Batching can limit clinical applicability, as real-world usage typically involves unbatched inputs.
    • Grand Challenge's result viewer does not support displaying batched outputs.

Using a combination of these measures will help you maintain a fair, scalable, and cost-conscious challenge design.