We haven't even reached a stage where you can buy a single PCI Express 3.0 add-in card, yet the PCI-SIG isn't resting on its laurels as the company has just announced version 4.0 of the PCI Express specification. As you might expect PCI Express 4.0 is bringing twice the bandwidth compared to PCI Express 3.0, but it's not going to arrive any time soon.With only Intel's recently announced Sandy Bridge-E processors and X79 based motherboards having the potential of offering PCI Express 3.0 support, that is if Intel ever condones it officially, we're currently at a stage where PCI Express 3.0 doesn't matter all that much. That said, come next year we should see a wider availability of PCI Express 3.0. With twice the bandwidth of PCI Express 2.0, a standard that is hardly being utilized to the max, one has to wonder what we can look forward to that will use up the bandwidth of PCI Express 4.0.With some 16GT/s (that's gigatransfers) we're looking at a lot of bandwidth here and the good news is that the PCI-SIG is expecting this to be feasible with little to no changes to the physical PCI Express 3.0 board and slot layout, much in the same way as the move from PCI Express 2.0 to 3.0. That said, the PCI-SIG isn't expecting to have the finer details of PCI Express 4.0 done until sometime in 2014 or 2015 and by then, there might be something that needs all that extra bandwidth. Keeping with the good news, PCI Express 4.0 is expected to be fully backwards compatible, cost no more to make than current PCI Express implementations and we might be seeing some more power efficient implementations developed by the time the standard is finalized.
Read more: PCI Express 4.0 announced, twice the bandwidth of 3.0 by VR-Zone.com