It seems like only yesterday we were dealing with AGP 8x cards, doesn't it? Well, actually, it's more like a couple years ago - AGP's replacement, PCIe, has already been with us for more than two years. Now, the PCI Express design is getting an overhaul - the new PCIe 2.0 standards
have been ratified by PCI-SIG, the group that handles PCI bus standards.
When it was designed, PCIe was supposed to be a real futureproofing - 75W of power and 2.5Gbps of bandwidth (a 16x card could pull nearly 8Gbps) right through the slot. This eliminated the need for external power and greatly exceeding AGP's not even half-used bandwidth constraint. Of course, the latest cards (such as the NVIDIA 8800 GTX) are already on their second independent power connector, drawing a whopping 185W of power.
In order to compensate, PCIe 2.0 has modified the power standard. The previous 6-pin 75W connector has now been retired, moved instead to an 8-pin 150W connector (see the Inquirer
for a picture). Bus speeds have also increased to 5Gbps, meaning that a 16x card can now potentially pull up to 16Gbps. Of course, current cards are a long way from even maxing out the PCIe 1.1 interface, so this is much more of a theoretical improvement.
Intel will be expected to release the first compatible chipsets in the start of 2Q 2007 with the Bearlake codename. Along with the new PCIe 2.0, these boards will feature the ICH9 southbridge, DDR3 support, and a 1333MHz FSB. The PCIe 2.0 interface will be backward compatible with current-generation cards, so you don't need to worry about buying new graphics cards if you buy one of these boards.
Whether the move is necessary for anything but the convenience of the new power connector is not something we can easily determine. However, it does provide that much more theoretical headroom to play with - hopefully, we'll start seeing cards make use of it.
Have you got a thought on the improvements? Tell us about it in our fourms