Quote - The AA, 2 pixel accuracy, 2 pixel shadow accuracy , fast 16 pixel lighting quality is pretty much Carrara's default settings.

Only thing changed really was enabling Global Illumination: Sky Light  & Indirect Lighting, Light Through Transparency and Caustics (mostly default values for those, just enabling them).Only thing being affected by Light through Transparency and Caustics

Hello
I have read in threads at Daz Forum that GI increases demand for memory. Some people have used lights attatched to domes as an alternative.
Also you should check to see how much phisical memory you actually have available in task mamager.
On windows XP 32, Windows Takes some memory for your video buffer. How much it takes depends on your video configuration,
and or card type. This can be 100s of megabytes.