Beyond3D: In previous interviews you've mentioned using multi-threading to help speed up streaming new areas. How important are you finding the other, less visible, system parts like memory speeds, CPU L2 cache, AGP/PCIe speeds, etc. in this regard?

Gavin: We've found it's definitely a total picture situation as far as optimization goes. For instance, we've spent some time optimizing our code to prevent L2 cache misses and made some gains there. We try and take optimal advantage of every hardware component, so any extra speed we can get out of any part factors into the overall picture.

Beyond3D: We're also curious about any figures you care to divulge about average triangle and vertex loads per scene. Approximately how many pixel shaders will the game have, and if you can answer how many instructions on average do your pixel and vertex shaders have?

Gavin: Suffice to say that our triangle and vertex counts are on the high side, but in line with what Microsoft and the major video card companies recommend for next-gen development. For pixel shaders, if you take into account all the different configurations that result from compiling for different cards, there are hundreds. However, there are probably about 25 major shader effects that are utilized in general situations. The instruction count scales with shader model, so our lower-end 2.0 shaders are kept pretty compact while the 3.0 lighting shaders are quite long and will appreciate a fast video card.