Forum Discussion
Fabric Cost optimization
Hello Mmoustaqssa
You're right, downgrading to a F32 capacity means you'll need more Power BI Pro licenses for your report/dashboard consumers.
Switching back to a P1 capacity won't work either! Microsoft has officially retired P SKUs. Customers were able to renew their Power BI Premium capacity subscriptions until February 1, 2025. Customers who had a renewal date after February 1, 2025 had to replace their Power BI Premium capacity subscription purchase with the purchase of Fabric capacity at the end of their agreement. It is described here -
Important update coming to Power BI Premium licensing | Microsoft Power BI Blog | Microsoft Power BI
However, if you're currently using F64 PAYG, you can upgrade to a F64 Reserved capacity. This will be the best option in your case. You don;t need to "switch" the capacity itself, you just buy a discount voucher (the Reservation) that automatically covers the cost of your running capacity.
The process is strictly a billing change in the Azure Portal.
1. Go to "Reservations": Search for Reservations in the Azure POrtal
2. Purchase Microsoft Fabric Reservation: Click + Add, select Microsoft Fabric, and choose the 1-year term.
3. Match the Region and CUs:
a) Region: select the exact same region where your F64 capacity is running.
b) Quantity: enter F64
4. Complete purchase: once you buy, Azure's billing system sees you have an active F64 reservation. It will automatically stop charging the PAYG rate.
Microsoft EmployeeYou can downgrade to Fabric F32, but a couple of important things to be aware of.
First, the cost increase you’re seeing after moving to F64 isn’t because you’re actively using Lakehouse, Notebooks, or Data Engineering. It’s because Fabric is billed per capacity and pay as you go model. With F64, you’re paying for 64 CUs all the time the capacity is running, even if you only use Power BI.
Regarding the report access:
To view Power BI content with a Microsoft Fabric free per user license, your capacity must reside on an F64 or larger SKU, and you need to have a viewer role on the workspace. https://learn.microsoft.com/en-us/fabric/enterprise/licenses
So if you downgrade to F32, users with a Free Power BI license won’t be able to view reports anymore, they’ll need a Pro license.
In the case you want to reduce costs while maintaining free per user licence accesses, i would consider a common approach that is to keep F64 but automate pause/resume of the capacity. You can use an Azure Logic App to stop the capacity outside business hours (nights/weekends for example) and start it again in the morning. Since Fabric is billed while the capacity is running, this can cut costs significantly without changing SKUs.
You can have a look at this article regarding the automation : Never Pay for Idle Azure Fabric Capacity Again: Au... - Microsoft Fabric Community
what about to switch to a F64 Reserved capacity ?
- valentinbauer
If you switch to an F64 Reserved capacity, you’re no longer paying based on uptime of the capacity. You’re committing to the capacity 24/7 for 1 year, and you pay for it whether it’s running or paused.
So in practice:
Reserved F64 : You pay upfront (or monthly) for the full year, cost is fixed and discounted but pausing the capacity will not reduce cost anymore (since you reserved the capacity)
Pay as you go F64 : You pay per hour of runtime, pausing the capacity does stop compute billing and Logic Apps pause/resume allow real savings
As a quick summup for you to find the best fitted solution:
- If your capacity have to run most of the time (≈ 24/7), then a reserved F64 makes sense
- If your capacity run only on specific business hours, keeping pay as you go and adding auto‑pause will be cheaper
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