Forum Discussion
Fabric Data Agent CU Calculation based on Query
I ran 10 queries in my Fabric Data Agent . Approxomately 10 queries have 100 input words and 1100 output words, roughly transalte into 135 input tokens and 810 output tokens.
Added to this I have given Agent Instrcution and DB Set up and Examples which is around 545 words, which we can calculate 10 times, 1 for each query.
As per the calculation mentioned in https://learn.microsoft.com/en-us/fabric/fundamentals/data-agent-consumption
This should be only ~1100 Cu seconds.
In the Capacity metrics app it is showing 53992 Cu Seconds, when I checked for this Agent for the same day.
Not sure why is this huge difference?
Your estimate only includes LLM token usage, but Fabric Data Agent CU includes full execution cost.
The gap comes from:
-
multiple LLM calls per query (not just one)
-
schema + prompt expansion on every call
-
SQL/Spark execution on data
-
retries and query corrections
-
metadata scans and grounding
So 10 queries ≠ 10 executions. It is usually 3–7x more operations, and data compute dominates CU, which is why you see ~54k instead of ~1k.
Recently I discussed about this in detail in my blog. Hope this will help.
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3 Replies
Your estimate only includes LLM token usage, but Fabric Data Agent CU includes full execution cost.
The gap comes from:
-
multiple LLM calls per query (not just one)
-
schema + prompt expansion on every call
-
SQL/Spark execution on data
-
retries and query corrections
-
metadata scans and grounding
So 10 queries ≠ 10 executions. It is usually 3–7x more operations, and data compute dominates CU, which is why you see ~54k instead of ~1k.
Recently I discussed about this in detail in my blog. Hope this will help.
-
Hi Mahadevanp ,
Thank you for posting your query in the Microsoft Fabric Community Forum, and thanks to Vinodh247 for sharing valuable insights.
Could you please confirm if your query has been resolved by the provided solution? This would be helpful for other members who may encounter similar issues.
Thank you for being part of the Microsoft Fabric Community
Hi Mahadevanp,
Just checking, the issue been resolved ? Sharing an update can really help others wo may facing the same thing.
Thank you.
