The official specifications for the PCI Express 4.0 standard have finally reached version 1.0. The first time we talked about this was last June, when we explored its main features. Beyond the long wait, PCI Express 4.0 will double the performance of its predecessor, with a total of 16 gigatransfers per second, and a full duplex x16 bandwidth of 64 GB/s. The announcement also highlights small advances in the 5.0 specification, which targets mid-2019.
The latest generation of graphics cards has given us formidable performance, and the best part is that it can be poured into older computers, courtesy of the backward compatibility in the PCI Express standard. Something quite common these days is to take a Dell or HP system (with limited options in terms of space and upgrades), acquire a suitable graphics card (say a GT 1030 or an RX 550, both in low-profile version), plug it into the PCIe slot and turn that humble computer into a very interesting gaming machine. This wouldn't be possible without the work of PCI-SIG, which instead of sacrificing each version to the hardware gods, managed to preserve electronic and mechanical compatibility while increasing performance at the same time.
What follows on the PCI Express list is its 4.0 specification, officially released earlier this week. Considering that PCI Express 3.0 was presented in November 2010, PCI-SIG took almost seven years to optimize the technical aspects of the standard, but we must recognize that it arrives at one of the best moments in the market. PCI Express is no longer an “exclusive” technology for graphics cards, so to speak, and its benefits are revolutionizing the storage world, with very fast products based on the M.2 format.
With a bandwidth that ascends to 64 gigabytes per second in x16 mode, PCI Express 4.0 will probably give another opportunity to multi-GPU configurations. Both Nvidia and AMD decided to “reduce” their efforts regarding SLI and CrossFire (a name that Sunnyvale retired recently) for the simple fact that developers do not implement these solutions, and the expected performance does not materialize. According to PCI-SIG, the initial adoption of PCI Express 4.0 is unprecedented, and if all goes well, it will reach store shelves during the first half of 2018.
