User-1174608757 posted
Hi Micco,
According to your description, the performance is slow because it will waste time to build connection to database and render data in browser. So when it has a large amount of data ,it will cause much time.So to solve this problem, you could try below ways.
1. Adding <trust legacyCasModel="true" level="Full"/> to web.config.
2.It will save time if you set your .net framework to 3.5
3.Try to optimize your sql query
Best Regards
Wei