What are the cases in which this would differ? Really struggling to find why this would ever be different.
Look at 1 project, not filtering by anything, have Sprint in Rows to show totals for each sprint. Seems to be different way more often then not
In Jira Velocity chart, it seems that only committed issues that are not completed at the sprint start moment are taken into account.
In eazyBI, Sprint Story Points committed looks for all issues that are assigned to the sprint at the sprint start moment.
To get the number of issues committed and not completed at sprint start moment, create a new measure where subtract committed completed issues from all committed:
[Measures].[Sprint issues committed]-
([Measures].[Sprint issues committed],