Quick Tech Question

[dgood]

What is the difference between normal pci-e x16 and pci 2.0?

[Apoptosis]

PCI Express 2.0 increases the bus data rate from 8GB per second to 16GB per second, so it actually doubles the bandwidth on this critical PC graphics interconnect. The PCI Express 2.0 specification is key for moving data quickly as the system RAM needs to be accessed to get data for large textures or vertex caches and as a result gaming performance has increased on platforms that have a PCI Express 2.0 motherboard and graphics card by as much as 22% from the testing that we have seen. It just doubles the bus... nothing more to it.

[Apoptosis]

of course there is this from wikipedia:

PCI-SIG announced the availability of the PCI Express Base 2.0 specification on 15 January 2007. PCIe 2.0 doubles the bus standard's bandwidth from 2.5 Gbit/s to 5 Gbit/s, meaning a x32 connector can transfer data at up to 16 GB/s in each direction.

PCIe 2.0 is completely backward compatible with PCIe v1.x, so graphic cards and motherboards designed for v2.0 will be able to work with v1.0 and vice versa. The transition to PCIe 2.0 won't be anything like the move from AGP to PCIe. The cards and motherboards are backwards and forwards compatible. PCIe 1.0 and 1.1 compliant cards can be plugged into a PCIe 2.0 motherboard, and PCIe 2.0 cards can be plugged into older motherboards. 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.

[dgood]

cool, I was just curious as to how big of an improvement it was in speed I guess and if only newest cards could take full advantage of the higher bus speed. Or if it just allows for more cards.

[Zertz]

PCIe 2.0 doubles the bus standard's bandwidth from 2.5 Gbit/s to 5 Gbit/s, meaning a x32 connector can transfer data at up to 16 GB/s in each direction.

So all those boards claiming increased bandwidth with PCI-E 2 = false advertising? You can't really magically double the bandwidth without any modification to electrical specs... So what you get is a PCI-E 2.0 interface (32 lanes) divided into 2 slots, giving you dual 16x slots, meaning it's not faster than PCI-E 1.

Anyways, it's not like PCI-E 16x bottlenecks anything... yet.

[kappage]

how do you tell if your motherboard supports it?