PCIE 4.0: News Trust Us, We’ll Need It

When people hear the words PCIe 4.0, they invariably pop off that they see no need for it because PCIe 3.0 has more than enough bandwidth. Now, pretend you’re sitting in gridlocked traffic on an L.A. freeway and squawk some more about not needing more bandwidth. You build the lanes before the congestion brings the entire system to a grinding halt, capiche? With that said, PCIe 4.0 is not a 2014 technology. In fact, we’d be surprised if we saw it in 2015—even though the spec is expected to be 90 percent done by then. PCIe 4.0 again doubles bandwidth, taking PCIe 3.0’s 8Gb/s speeds to 16Gb/s. A x16 PCIe 4.0 slot on a 2015 motherboard could theoretically transfer a whopping 64GB/s. And lest you think the PCI-SIG is ceding everything to Thunderbolt (which supports the PCIe protocols), the group is working on an external PCIe spec and cable called OCuLink, with speeds supporting up to 32Gb/s in each direction.