Why does SL need so much memory?

Though I am a hardware developer, I have an idea how SL works. If you look at the screen resolution, the color depth and the amount of RAM SL needs, you will find that the required RAM is enough to store hundrets of complete frames. But - SL does not fill the RAM with complete frames. It calculates triangles, uses textures, and overall this is a much more compressed way to generate frames. If you compare what you see on the screen, the number of pixels, to the amount of required RAM, there will be a huge mismatch. A SL frame consists of about 2MB (pixels), generated by triangles and textures, which reduces the amount of RAM space needed for a frame. OK, it is 3D, there is a Z-axis as well... but I really wonder what SL does with 1GB RAM. At Flight Simulator 2004, if I set the viewing range to 200miles (not meters!), I can fly around the whole globe at any height, detail, etc., but it will need only a fraction of that amount of RAM that SL needs. And FS2004 contains a lot of randomly generated objects as well, weather, clouds, winds, other planes, ships, cars... does anybody have a good answer?
Horst

textures

3D has a LOT more detail per frame than 2D. When you are looking at 2D (1024x768 at 32bpp, for example; 3.1MB), you're just seeing under a million display elements (pixels). 3D scenes may be generated from MILLIONS of larger and more detailed/complex display elements.

Modern video hardware has some neat tricks to optimize the display of all that data so that it doesn't choke (plus a cubic arseload of silicon horsepower to crunch through it), but you still can have a huge many-megabyte dataset to generate that single 3.1MB frame.

Programs like FS2004 are designed to take advantage of all kinds of tricks to optimize both the speed of the game as well as how much space they take up. Some tricks can work in other games, but many won't. SL is the worst-case scenario. Because of the open nature of its architecture, it can't implement a lot of these tricks (Binary Space Partitioning and Portals, as examples). As such it won't be able to have near the performance of a focused-development game, and will be both speed and space-inefficient.

Another trick that a lot of games can take advantage of is limiting textures and models, carefully designing them so that fewer, smaller textures/models, layered together or otherwise combined, can make a very detailed world. SL doesn't have that luxury, because everyone can upload anything and everything, including textures which are HUGE (often unnecessarily so) to be displayed on small objects. As such, you are getting streamed down other people's inefficient designs and assets, which means even more resource usage on your local system.

be glad we cant use 4096x4096 textures anymore, they all got limited to 1024x1024.