VIA and SiS Battle for Supremacy: 3-way P4 DDR Motherboard Roundup

AGP 8X Functionality?

In our P4X333 article back in May of this year, we mentioned that we were unable to operate the P4X333 using an AGP 8X compatible SiS Xabre 400 video card. We recently received confirmation from VIA that AGP 8X was indeed broken in the P4X333 chipset, which is why we couldn’t reliably run the Xabre card at AGP 8X in our P4X333 board.

The P4X400, however, has functional AGP 8X according to VIA and several motherboard manufacturers. We have also been told by SiS and other motherboard manufacturers that AGP 8X is functional on all SiS 648 boards. While we put lots of faith in the chipset and motherboard maker’s claim that their boards are capable of AGP 8X, we can’t confirm for certain until we get a hold of a reliable AGP 8X card to test. We will be able to confirm this in one of our upcoming roundups.

In addition, when we do finally receive a reliable AGP 8X compliant video card for an extensive period of time, we’ll see if that 2.1 GB/s of peak bandwidth does any good in the real world. However, our feeling is that AGP 8X is going to be just another marketing gimmick for now, worth basically nothing in today’s applications.