I have a layer with 400 point features that display a picture marker symbol on the map. We expect this number to increase a great deal. Unfortunately it's already noticeably slow. This is being rendered through a GIS portal written in C#, but it's also not that great when viewing through ArcMap. I'm pretty sure it's a performance thing with the PictureMarkerSymbol.
Is there a way to boost it's performance? If not, are there other options for displaying custom icons for map points?