Answer (1 of 3): How fast is PCIe 4.0 vs. PCIe 3.0? PCIe 4.0 is twice as fast as PCIe 3.0. PCIe 4.0 has a 16 GT/s data rate, compared to its predecessor’s 8 GT/s. In addition, each PCIe 4.0 lane configuration supports double the bandwidth of PCIe 3.0, maxing out at 32 GB/s in a 16-lane slot, or...