A very fast SSD, no matter which generation of PCIe you use.

Seagate’s FireCuda 520 is fast, though only on a par with other premium M.2 NVMe SSDs we’ve tested using commonplace third-generation PCIe. However, if you’re running a late-model AMD system, the 520’s PCIe 4 support will garner you a cool 20-percent jump in sustained transfer rates. We like that.
…
Read full post here:
https://www.pcworld.com/article/3453638/seagate-firecuda-520-nvme-ssd-review.html