PCIe 2.0 is completely backwards compatible with PCIe v1.x. Graphic cards and motherboards designed for v2.0 will be able to work with v1.1 and v1.0, and vice versa. The PCI-SIG also said PCIe 2.0 also features improvements to the point-to-point data transfer protocol and its software architecture. In June 2007 Intel released the specification of the P35 chipset which does not support PCIe 2.0 only PCIe 1.1. Some people may be confused by the P35 block diagram which states the Intel P35 has a PCIe x16 graphics link (8 GB/s) and 6 PCIe x1 links (500 MB/s each), for simple verification one can view the P965 block diagram which shows the same number of lanes and bandwidth but was released before PCIe 2.0 was finalized. Intel's first PCIe 2.0 capable chipset is the X38 and boards are already shipping from various vendors (Abit, Asus, Gigabyte) as of October 21, 2007. AMD starts supporting PCIe 2.0 from its RD700 chipset series. NVIDIA has revealed that the MCP72 will be their first PCIe 2.0 equipped chipset.
yes. but to fully optimize it on a non 2.0 was the question. compatable yes. like usb 2.0 is compatable with the one before 2.0...just runs a little slower. he was askin if you can upgrade to 2.0 your current pcie.
Q5: Then PCIe 2.0 must be backward compatible with PCIe 1.1 and 1.0? A5: Yes. The PCIe Base 2.0 specification supports both the 2.5GT/s and 5GT/s signaling technologies. A device designed to the PCIe Base 2.0 specification may support 2.5GT/s, 5GT/s or both. However, a device designed to operate specifically at 5GT/s must also support 2.5GT/s signaling. The PCIe Base specification covers chip-to-chip topologies on the system board. For I/O extensibility across PCIe connectors, the Card Electromechanical (CEM) and ExpressModule™ specifications will also need to be updated, but this work will not impact mechanical compatibility of the slots, cards or modules. Currently, the PCI-SIG is defining the PCIe CEM 2.0 specification which has been released to members for review at v0.5. There are currently no plans to adapt the PCIe Mini CEM specification for the faster bit rate as the market need has not yet materialized.