Performance and Cost Considerations from Power BI Pro/PPU to Fabric

What performance and cost considerations should you keep in mind if you are currently on Power BI Pro/PPU, but Fabric looks increasingly enticing and you want to upgrade an existing workspace to Fabric? For example, let’s say you’ve started with a pay-per-user workspace, but now you want that workspace to have Fabric features, such as Copilot, Lakehouse, etc. Or, as a typical use case for small to mid-size companies, you could have a Corporate BI workspace with org semantic model(s) that you want to transition to Fabric, such as to take advantage of DirectLake.

Performance

Performance is difficult to translate because Power BI Pro/PPU run in a shared capacity, meaning compute resources (v‑cores) are pooled across many tenants and dynamically allocated, whereas Fabric capacities are dedicated, meaning that Microsoft grants specific resources expressed as number of cores and memory. Therefore, Fabric performance is predicable while Pro/PPU might not be, although I’m yet to hear from client complaining about unpredictable performance.

Also, keep in mind that Power BI Pro limits you to a quota of 1 GB per dataset, PPU to 100 GB per dataset, and Fabric starts at 3 GB per dataset with F2 and doubles the grant up the chain. This is important for semantic models with imported data.

Although the tool wasn’t designed for estimating upgrade scenarios, you could start with the Fabric Capacity Estimator (preview) to get an initial ballpark estimate for the Fabric capacity. Start low, then monitor the capacity performance using the Microsoft Fabric Capacity Metrics app and be prepared to upgrade if necessary, such as when more parallelism is needed. 

Cost

This is easier. Here are the advertised, undiscounted and unreserved prices:

• Power BI Pro: $14/user/month (free with M365 E5 plan)
• PPU: $24/user/month ($14 discount with M365 E5 plan)
• Fabric: Starts at $262.80 per month with F2 and doubles the price up the chain. Finding what capacity you need requires evaluating what workloads you will be running to ensure you have enough resources.

It’s important to note that Fabric capacities lower than F64 require a Power BI Pro license for every user who accesses shared content, regardless of viewing or creating content. Microsoft Copilot and ChatGPT got this wrong by adamantly claiming that viewers don’t require Pro license, while Grok got it right, so be careful which agent you use when researching. The Fabric Capacity estimator also correctly identifies the required Pro licenses.

Of course, Fabric gives you features unfortunately not available in the pay per user licensing plans, so the actual decision in favor of Fabric will probably transcend just performance and cost. When evaluating the performance of the lower Fabric SKUs, you might find the following blogs I wrote on this subject helpful:

Notes on Fabric F2 Performance: Warehouse ETL

Notes on Fabric F2 Performance: Report Load