Reprojection performance

Discussion created by david_allan on Mar 20, 2014
Latest reply on Mar 21, 2014 by JQuinn-esristaff
I have a web app using web mercator due to the basemap spatial reference. On top of this I need am overlaying some data held in 27700.

Is there any difference in terms of performance between the following options:

1) Publish the 27700 data in a service in 27700 and let ArcGIS Server reproject it when a request for data in 102100 is received from the web app.

2) Publish the 27700 data in a service using a data frame set to web mercator meaning from the rest end point the projections appear to match, but I presume the same reprojection operation is still occuring internally