That sounds about right. The only cards with 4x and 8x versions are really the Geforce 4 Ti 4200 and MX models. The MX models arent really worth bothering with if you're interest in AGP 8x performance, as they're based on Geforce 2 chipsets. In the Ti 4200 case, the 128MB models were actually bettered, with the memory speeds increased from 444MHz to 512Mhz and bandwidth increased from 7.1 to 8.0 or 8.2 Gb/s. This does make a marginal performance increase, but the 8x AGP does nothing for it. It shouldn't even be a factor in deciding on a graphics card, as it makes absolutely no difference, even in intensive graphics, such as dx9 games.
Hope that helps.
This thread is now locked and can not be replied to.