How Big Is the San Andreas Map, and How Did a PS2 Hold It?

The headline number for Grand Theft Auto: San Andreas is often given as roughly 36 square kilometers, which is several times the area of the maps in Grand Theft Auto III and Vice City. Numbers like that are always approximate, since they depend on how you count water and unreachable terrain, but the conclusion is not in dispute: this was a much bigger game than its predecessors, released in 2004 on a console that was, by then, several years old.

That console is the interesting part. The PlayStation 2 had about 32 megabytes of main memory, which is a tiny amount by any modern standard. There is no way to hold a state’s worth of geometry, textures, vehicles, pedestrians and audio in that space at once. The answer, which the series had been developing since Grand Theft Auto III, is streaming: the game continuously loads the parts of the world near the player and discards the parts behind. The DVD is effectively part of the working memory, and the player’s movement drives what is read from it.

Streaming has consequences that anyone who played the game will recognize. Objects and distant buildings can pop into view as you approach. Draw distance is limited. Moving quickly, especially in the air, can outrun the loader and produce moments where the world has not caught up. Interiors, which are treated as separate spaces, involve a brief transition. These are not bugs so much as visible seams in a system doing something ambitious with limited resources.

As I read it, the design also works with the hardware rather than against it. The countryside has a lower density of detail than the cities, which eases the load while still delivering a sense of distance. Far-off objects are drawn cheaply. Long stretches of relatively empty road are atmosphere, but they also plausibly give a streaming system room to breathe. Some of what reads as artistic pacing may double as technical strategy.

It is worth noting that the game ran on RenderWare, a third-party engine and middleware suite rather than a fully in-house technology. That is a point of contrast with the following generation, when Rockstar moved to its own in-house engine for Grand Theft Auto IV in 2008.

I find this kind of constraint-driven design more impressive than raw scale. Any game with enough memory can be big. Making a big world feel continuous on hardware that cannot hold it takes a chain of decisions about what to load, what to fake, and what to leave out. That the result still feels like a single place, rather than a series of loading screens, is the accomplishment.

When people say old games “could not do that today,” they usually get it backward. Modern hardware can do it easily. The interesting question is why the compromises on this one still hold up. My answer is that a well-designed seam is invisible until you look for it, and San Andreas rarely made you look.