ATI’s Radeon 9700 (R300) – Crowning the New King

The 2nd with AGP 8X

The first stage in the 3D pipeline is the most obvious, sending commands and data to be executed on the graphics chip. This function is initiated by the software running on the host CPU, sent over the AGP bus and finally reaching the graphics processor, which is contacted using the graphics drivers.

The R300 improves on previous chips by implementing an AGP 8X interface between the GPU and the North Bridge of your motherboard’s chipset. As you’ll remember from our P4X333 Review, the AGP 8X specification (AGP 3.0) runs at 66MHz and transfers data eight times per clock cycle. The 32-bit wide AGP bus when running in 8X mode results in a total of 2.1GB/s of bandwidth between the R300 and your PC’s North Bridge.

Although we have yet to see scenarios where even AGP 4X is absolutely necessary, it does make sense to continue to increase the amount of available AGP bandwidth. The R300 is backwards compatible with AGP 4X for use with most present-day systems.

The GeForce4 and all competing solutions currently employ AGP 4X interfaces but by the end of this year you can expect to see updated versions of most major cards with AGP 8X support. ATI can’t claim the title of first with AGP 8X since SiS pulled that off with the Xabre, but claiming AGP 8X support at this point doesn’t really exude a performance advantage.