Intel Developer Forum Day 3 - More from the Tech Showcase

PCI Express on Desktops in 2004

Yesterday we mentioned that Intel's roadmap for PCI Express put it on desktops by 2004, which means device availability will have to be a reality by the end of this year.

From talking to the PCI-SIG and Intel, it seems like we'll find two PCI Express slots in the first implementations of express-enabled desktops. Remember that PCI Express is a very low pin-count, high-bandwidth serial interface that can be widened in order to provide more bandwidth. A single x1 PCI Express link can offer 2.5Gb/s of bi-directional bandwidth, and the specification currently allows for links of up to 16x in width - the x16 interfaces are currently focused almost exclusively on graphics. The two slots that will make it onto desktops initially will most likely be a x1 and a x16 slot; the x1 slot for peripheral expansion and the x16 slot as a replacement for AGP.

At first, there will be AGP-to-PCI Express bridges, but the goal is to eventually make video cards have a native PCI Express interface. ATI has already shown off a Radeon 9700 with an AGP-to-PCI Express bridge, to illustrate how quickly current generation graphics can be moved over to PCI Express.

One of the major advantages of the PCI Express interface over AGP for graphics happens to be that the AGP specification only allows for 20 - 40W of power for graphics cards, whereas PCI Express will support power consumption of approximately 60W. Looking at the GeForce FX with its 70 - 75W power draw, we wonder if even the boosted power PCI Express will be too little given the way GPUs are increasing power consumption.

Final Words

We're in the home stretch now, having just finished day 3's keynote, all we have left is the highly anticipated talk by Pat Gelsinger tomorrow and a handful of NDA briefings before we head back to the melting ice and snow on the East Coast.

We hope you've enjoyed our coverage thus far, there's still more to come so keep on checking back.