Forum Discussion
Community ChampionUnused measures affecting performance?
Hi all,
Imagine we have a poorly maintained model with a relatively high number of measures, say 60, that are no longer in use. Not used in any visual nor by other measures.
Could these measures have any negative effect in the performance of the model/dashboards?
Many thanks
Hi, AlB
They won't. Performance is affected by the visuals you have on the report pages and how many values need to be calculated with the measures used in those visuals.
Let me quote from a blog here：
Measures are calculated on the fly!
Measures are not pre-calculated values. The only type of calculation in Power BI, which is not pre-calculated is the Measure. Measure calculation will happen on the fly, right at the time when you change a value in the slicer, filter, or click on a visual to highlight something. Every interaction like those will trigger the evaluation of a measure to happen.
Measures Consume CPU
Because Measure calculation should happen immediately after the interaction through other visuals, this calculation happens using the processing unit of CPU. At the time of calculating measures, you can sometimes notice it (if the calculation takes a long time) that the CPU usage suddenly goes up to 100%, and after finishing the calculation goes back down.
Measures Consume Memory! Yes, they do sometimes!
Measures are mainly consuming the CPU, however, they sometimes also consume memory.
Although the measure itself is not stored anywhere and doesn’t take memory for storing the final output, there might be memory consumption for temporary calculations. This memory consumption is not just happening with iterators. there are other scenarios functions and expressions that might cause this.
For reference: Why my Power BI Matrix or Table Visual is SLOW
If you wish to identify unused measures in your model or optimize your model, here are some blogs that will be helpful to you.
https://www.thebiccountant.com/2020/01/01/tidy-up-power-bi-models-with-the-power-bi-cleaner-tool/
https://radacad.com/power-bi-cleanup-tool-time-saving-with-power-bi-helper
Hope this helps.
Best Regards,
Community Support Team _ Zeon Zheng
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
2 Replies
- v-angzheng-msft
Community Support
Hi, AlB
They won't. Performance is affected by the visuals you have on the report pages and how many values need to be calculated with the measures used in those visuals.
Let me quote from a blog here：
Measures are calculated on the fly!
Measures are not pre-calculated values. The only type of calculation in Power BI, which is not pre-calculated is the Measure. Measure calculation will happen on the fly, right at the time when you change a value in the slicer, filter, or click on a visual to highlight something. Every interaction like those will trigger the evaluation of a measure to happen.
Measures Consume CPU
Because Measure calculation should happen immediately after the interaction through other visuals, this calculation happens using the processing unit of CPU. At the time of calculating measures, you can sometimes notice it (if the calculation takes a long time) that the CPU usage suddenly goes up to 100%, and after finishing the calculation goes back down.
Measures Consume Memory! Yes, they do sometimes!
Measures are mainly consuming the CPU, however, they sometimes also consume memory.
Although the measure itself is not stored anywhere and doesn’t take memory for storing the final output, there might be memory consumption for temporary calculations. This memory consumption is not just happening with iterators. there are other scenarios functions and expressions that might cause this.
For reference: Why my Power BI Matrix or Table Visual is SLOW
If you wish to identify unused measures in your model or optimize your model, here are some blogs that will be helpful to you.
https://www.thebiccountant.com/2020/01/01/tidy-up-power-bi-models-with-the-power-bi-cleaner-tool/
https://radacad.com/power-bi-cleanup-tool-time-saving-with-power-bi-helper
Hope this helps.
Best Regards,
Community Support Team _ Zeon Zheng
If this post helps, then please consider Accept it as the solution to help the other members find it more quickly. 
CNENFRNLAFAIK, measures evaluate on the fly. I doubt any negative impact on performance if they are not used (directly or indirectly referenced).