Optimization Optimizing Summoner is generally pretty challenging. Potential candidates for optimization are found by going through all the levels and looking for slow spots. Summoner contains some basic diagnostic code that helps identify reasons why the game is running slower than it should. They identified the texture upload problem already mentioned, among a few others. If the game is still running slower than it should, it's time to break out the profiling tools and see where things are going.
Some optimizations are level changes.
Some levels have had the number of visible polygons reduced to an acceptable level for a Voodoo 2. Some lightmaps have also been removed from some areas, and vertex lighting used in its place. Vertex lit meshes render faster and don't use as much texture memory. Some levels have had half their lightmaps removed with no difference in visual quality. The level file format has been reduced in size as well, although it will never be as small as the Ps2 version.