[sldev] Check this

[Argent Stonecutter]

People gripe at lag in SL with only 40,000 agents in-world.

If the "cloud" has to handle all the rendering for each agent, what's  
that going to cost? We're talking about more than a sim's worth of  
computations just for the rendering, and streaming every pixel in  
world over the Internet... the CPU and bandwidth requirements are  
insane. With 40,000 agents you're going to need a cloud many times  
the size of the SL grid to keep up.