F64 memory error

Hi wojciech 

Thanks for raising this — migrating from P SKUs to Microsoft Fabric capacities like F64 often reveals subtle differences in how memory and resources are managed.

To help pinpoint the issue, here are a few key questions to consider:

1) Have you enabled Large Model Format on your dataset?

Go to the workspace setting > License info > fabric capacity > Semantic model storage format and check if:

• Large dataset storage format is enabled

• The dataset is using enhanced metadata format

Without this, your model may be restricted to lower memory thresholds even on F64.

2) Have you reviewed the Capacity Metrics App?

• Are you checking per-dataset memory consumption and peak usage?

• Under Dataset Operations, do you see any throttling or resource contention during refresh times?

• Is your dataset refresh overlapping with other workloads (e.g., AI notebooks, pipelines, other dataset refreshes)?

3) Is your model optimized for Fabric?

• Have you reviewed high-cardinality columns or unused columns in the model?

• Are you using incremental refresh or partitions to limit the memory used during refresh?

• Could you reduce the dataset size with proper data filtering or summary tables?

4) Are you scheduling concurrent heavy workloads on the same capacity?

Fabric enforces isolation and resource quotas more strictly than Power BI Premium P SKUs. Even on F64, a large dataset may only get 15–20 GB of working memory depending on what else is happening on the capacity.

Hope it can help you!
Best regards,
Antoine