The next version of PCI Express was announced yesterday, promising data transfers of up to 2GB/s on a single lane, double the current rate of PCIe 3.0. PCI-SIG chose the target speed carefully to ensure backwards compatibility with the previous specification and to keep it cheap enough to manufacture that it can be widely adopted. The new spec should allow higher performance and lower power consumption by reducing the number of lanes required for high-speed data transfers — it isn't unusual for graphics cards to use as many as 16 PCIe lanes. The EE Times says PCIe 4.0 is expected to be the final copper-based PCI standard before moving to optical connections. There is still a lot of work to be done on the next spec, so it won't be ready until around 2014 or 2015 with hardware shipping sometime after that. Our Thunderbolt accessories should be able to make good use of the speed boost by then.
PCI Express 4.0 announced, will double throughput to 2GB/s
The PCIe 4.0 specification will allow data transfers up to 2GB/s on a single lane, double the rate of PCIe 3.0 — it should be ready some time in 2014 or 2015.