Comparing cost of Dataflows (Gen1 vs. Gen2 vs. Gen2 CI/CD) in Power BI and Fabric

UPDATE 16th October 2025

I have been using a Dataflow for years now which transforms a web log (.txt file) with many applied steps in Power Query and finally producing a nice table format to be used in my Power BI report. My raw data is about 20 GB or 150M rows.

This Dataflow Gen1 has been consuming lot of resources from our small F2 capacity. I have heard a lot about Dataflows Gen2 being expensive as well so I wanted to see what happens when I put exactly the same query in a new Dataflow Gen2.

Since 2025 Microsoft added a native Fabric artifact, a Dataflow Gen2 CI/CD with more features.

Migrating a Dataflow Gen1 to Gen2 can be done easily now by clicking on the options and "Saving as Gen2"

Migrating from old Gen2 to Gen2 with CI/CD can be done the same way.

Now let us look at the costs of running both Dataflows (in terms of CUs) and also the average refresh times.

Refresh time comparison (Dataflow Gen1 vs Gen2 vs Gen2 CI/CD)

	Gen1	Gen2	Gen2 CI/CD (scale settings on)	Gen2 CI/CD (scale settings off)
Low	49 min	32 min	70 min	34 min
High	52 min	34 min	74 min	39 min
Average	51 min	33 min	72 min	36 min

As you can see above, my Dataflows Gen2 refreshes the fastest. The new Dataflow Gen2 with CI/CD was basically the same speed but it depends on the scale settings.

Scale settings in Dataflow Gen2 with CI/CD

If you have the scale settings on it might be better or worse and depends on your data source. For me (.txt files in Sharepoint the scale settings actually had a negative effect). Make sure to test this well for your setup.

Next let us look at the costs, we measure them in Compute Unit seconds (CUs) which is what you get charged by in any Fabric capacity. You can find some basics here.

Compute cost comparison in CUs (Dataflow Gen1 vs Gen2 vs Gen2 CI/CD)

	Gen1	Gen2	Gen2 CI/CD (scale settings on)	Gen2 CI/CD (scale settings off)
Low	27,255	45,096	22,142	17,498
High	27,563	46,736	22,526	17,704
Average	27,409	45,916	22,334	17,601

The cost however, is highest for the "old" Gen2 meaning we are paying for the additional speed. I like that the Gen2 CI/CD dataflow is now much cheaper than my old Gen1 and it is also very fast.

I would recommend you test the refresh time and CU usage before migrating your Dataflows to check if it will meet your expectations. It seems however that the new Dataflow Gen2 with CI/CD will become the standard especially because it is cheaper than all previous generations and we know that costs have always been a problem.