Poor performance with Power BI API for paginated reports compared to SSRS

Hi mmouton 

Performance is slower with Power BI Paginated Report API than SSRS because rendering in Power BI runs through additional cloud service layers, capacity limits, and gateway latency, unlike SSRS which runs fully on-prem. This is expected behavior, not a bug.

To improve performance:

1. Optimize report queries and reduce data volume.

2. Simplify report layout (fewer visuals, subreports, expressions).

3. Use the Paginated Report Diagnostics tool to find bottlenecks.

4. Ensure your Fabric capacity isn’t throttled.

5. Minimize gateway latency or move data closer to Power BI (e.g., Azure SQL).

https://darren.gosbell.com/2023/10/diagnosing-performance-of-paginated-reports-in-power-bi/?utm 

https://learn.microsoft.com/en-in/power-bi/guidance/report-paginated-performance-scalability-considerations 

If the above steps don’t improve performance, here’s the next level of action:

1. Switch from DirectQuery to Import mode (if possible).

   • DirectQuery causes repeated round-trips through the gateway for every query.

   • Import mode caches data in Fabric, giving up to 5–10× faster rendering.

2. Run reports in Power BI Report Builder (desktop) for critical use cases faster than cloud rendering because it skips Fabric service overhead.

3. Scale up capacity to F8 or highe - paginated reports benefit from more RAM and rendering threads.

4. Move your SQL source to Azure (PaaS) - reduces gateway latency drastically compared to on-prem SQL.

5. Raise a Microsoft support ticket - if diagnostics show normal query time but high “rendering” time, it may be a Fabric backend issue.
   https://support.fabric.microsoft.com/