Express brought us much better performance for all sorts of add-in
cards including better graphics bandwidth. Not too long after the
original PCIe specification surfaced, we got the 2.0 update that
brought along even better performance, again helping gamers looking
for the best in video card speed.The PCI-SIG has announced
another update to the specification with the unveiling of PCI
Express 3.0 specification. The base spec for PCI Express 3.0 is
now available to all members of the PCI-SIG. The spec is a low-cost,
high-performance I/O technology that has a 128b/130b encoding scheme
and a data rate of 8 gigatransfers per second (GT/s). That is double
the available interconnect bandwidth of PCIe 2.0.The PCIe
spec is also backwards compatible with all earlier PCIe specs to
maintain compatibility with add-in cards on the market with new
mainboards. The original PCIe specification supported 2.5GT/s and
PCIe 2.0 supported 5GT/s. The PCIe 3.0 spec's 8 GT/s is sure to usher
in more improvements in graphics processing.
PCI-SIG says that a x1 PCIe 3.0 slot is capable of 1GB/s transfer
rate, and that transfer rate scales up to 32GB/s on a x16 lane. You
can bet once the new specification is available on mainboards we will
see lots of video cards supporting it hit market.“Each new
version of the PCIe spec has doubled the bandwidth of the prior
generation,” said Nathan Brookwood, research fellow at Insight 64.
“The latest group of PCIe architects and designers drove the
standard forward while maintaining complete backward compatibility
for Gen 1 and Gen 2 devices. Rarely has a standard advanced so
non-disruptively through three major evolutionary cycles. The ability
to pull this off demonstrates not only the ingenuity of the Gen 3
developers, but also the insight of those who defined the earlier
versions in such an extensible manner.”
quote: Marketing crap, don't need it!
quote: “Each new version of the PCIe spec has doubled the bandwidth of the prior generation,” said Nathan Brookwood, research fellow at Insight 64.
quote: The original PCIe specification supported 2.5GT/s and PCIe 2.0 supported 5GT/s. The PCIe 3.0 spec's 8 GT/s is sure to usher in more improvements in graphics processing.
quote: PCIe 2.0 delivers 5 GT/s, but employs an 8b/10b encoding scheme which results in a 20 percent overhead on the raw bit rate. PCIe 3.0 removes the requirement for 8b/10b encoding and instead uses a technique called "scrambling" in which "a known binary polynomial is applied to a data stream in a feedback topology. Because the scrambling polynomial is known, the data can be recovered by running it through a feedback topology using the inverse polynomial" but still uses a 128b/130b encoding scheme. PCIe 3.0's 8 GT/s bit rate effectively delivers double PCIe 2.0 bandwidth. According to an official press release by PCI-SIG on 8 August 2007:
quote: Network, graphics, Keyboard, mouse, audio, storage devices should all support basic functionality with a default driver for each class of device.