Do you need to process a lot of Common Data Service records as fast as possible? Then you should consider setting the Concurrency degrees of parallelism to as high a level as your service will support. In an earlier blog I did a test of updating 15,000 Account records. It took 168 minutes to retrieve the records and update two text fields. I didn’t make any changes to the default setting for the number of loops that would run at a time.
For the next experiment I then went in to the flow and edited the settings for the Apply to each action to move the slider all the way to 50.