The big way PCIe may affect you is storage speeds. Many people use PCIe based RAID cards and SSDs (both m.2 NVMes and PCIe cards). With the PCIe 4.0 specifications essentially doubling the bandwidth of each PCIe lane, we can see faster SSDs using the same number of lanes. As you may already know the current PCIe 3.0 m.2 NVMes max out at around 3500 MB/s sequential read/writes.
Now without the PCIe 3.0 bandwidth limitations getting in the way, new NVMes drives have been unveiled that support PCIe 4.0 using a new controller. Both Gigabyte and Corsair have announcements new drives. The new drive from Corsair will have speeds reaching 4950 MB/s sequential read and 4250 MB/s sequential writes. This is a huge improvement over the current generation SSDs and one that I think could foster innovation and bring new technologies for SSDs as companies now strive to max out 4 lanes of PCIe 4.0, which is about 8GB/s.
What would you do with these insanely fast SSDs? Let us know in the comments or on Twitter @iKillTheApple