Backface culling

In MBX light hardware, is the backface culling of polygon made by HW or is it software based into the driver ? Can we gain some speed by turning off backface culling of polygon when we know they are facing the camera all the time ?

On platforms without VGP backface culling might be performed in the driver in some cases, but the cost should be low. Anyway, it certainly won’t hurt to disable backface culling if you don’t need it.