It seems you're working on the assumption that filling a database with raster tiles is a good thing. There are many reasons why this is not so. Back at 8.0, when this capability was first offered, it was the only way to achieve pyramids, so the high overhead in database transaction space and storage and backup complications could be forgiven. It's been a long time since service caches were added to ArcGIS Server, and integration of image server capabilities into mosaic datasets finally drove the stake into the heart of raster catalogs.
Yes, if your base imagery is uncompressed, you should compress it, and serve that instead, but you don't need to use a catalog to accomplish this. Experimentation has shown that files on disk outperform tiles stored in databases. Simple and fast is better than complex and slow.
The number of images you have could be a distraction that is preventing you from getting optimal performance. If you mosaic your uncompressed images into 3x3 compressed composites, you'll reduce the number of images by an order of magnitude. and probably improve overall performance.
- V
