Use our 64bit code (fully supported by Lightsprint) whenever possible. With 64bit code, system memory is better utilized, you can process scenes of all sizes.

If you must use 32bit code (because your engine is 32bit only, e.g. UE3, Gamebryo), address space is severely limited by operating system, application can't use whole memory, purchasing more RAM usually does not help.

If you use Gamebryo Toolbench (32bit) and "Bake lightmaps" function fails due to insufficient address space, use "Calculate to cache" and "Bake from cache" functions. In 64bit Windows, it lets you process blocks of virtually unlimited size. In 32bit Windows, it lets you process bigger blocks at higher quality.

If you must use 32bit code, run it in 64bit operating system, this gives you 4GB of address space per-process. It is good enough for majority of tasks today.

If you must use 32bit Windows, use /3GB parameter in boot.ini, this gives you 3GB of address space per-process.

Using 32bit Windows without /3GB parameter is worst case scenario, process has only 2GB address space, so tasks like lightmap building can't process huge scenes.