You are using the Maplex Label Engine for computing labels on the fly. The Maplex Label Engine does an excellent job placing labels on the fly but will decrease performance due to the calculations involved. For this reason, the Maplex Label Engine is recommended only for cached map services when publishing map services. When working with a basemap layer, the Maplex Label Engine may decrease performance of map display between pan and zoom operations.
Check the drawing performance for your layer or basemap layer in ArcMap. If you are publishing, check the drawing performance for your service in the Preview window.
- If you need to make changes you can change on-the-fly map labeling to use the Standard Label Engine, which is faster. However, this can lower the quality of your label placement.
- Alternatively, you can precompute your map labels using the Maplex Label Engine, then save these as annotation features. Using this alternative, you would replace on-the-fly Maplex Label Engine labeling with annotation layers in your document.
There are three options for generating map text:
- Use the Standard Label Engine, which performs simple map labeling and places fewer map labels but has faster performance.
- Use the Maplex Label Engine, which does highly intelligent, advanced map labeling, saving significant editing time and placing more labels. However, advanced Maplex Label Engine capabilities can lead to poor performance and are only recommended for cached map services.
- Use annotation to save text labels that have been precomputed.
See An overview of working with text for more information.