When we saw the first prototypes in Taiwan last year, some manufacturers used Crush 17 and other Crush 18 as part of the name.
Back in those halcyon, non-toys-throwing-out-of-oran days when Nvidia still talked to us, it confirmed the IGP core inside chipset and made a big noise about how AGP8X was important, although it's not as important as all that.
To avoid confusion, all IGP Nforce 2 boards work with AGP8X discrete cards such is Radeon 9700, 9800, FX etc but the integrated core is AGP 4X only.
Apart from a marchitectural gain, AGP 8X does not make any noticeable performance difference but as even a precociously intelligent toddler knows, eight is two times four. µ