One of the first PCIe Gen 4 NVMe SSDs to market has been the Corsair Force MP600.
Seagate FireCuda 520 PCIe Gen4 NVMe SSD Linux Performance Review
Corsair Force MP600 PCIe 4.0 NVMe SSD Benchmarks On Linux Review
Crucial P2 Performance On Ubuntu Linux - An Affordable 500GB NVMe
Corsair MP600 PRO LPX SSD Review and Benchmark – Changing Gear
Corsair MP600 PCIe 4.0 NVMe SSD review (Page 3)
Corsair MP600 PRO LPX SSD Review and Benchmark – Changing Gear
Corsair MP600 PCIe 4.0 NVMe SSD review
Corsair MP600 PRO LPX SSD Review and Benchmark – Changing Gear
Solidigm P41 Plus NVMe SSD Review - Phoronix
Corsair MP600 Pro XT PCIe 4.0 M.2 NVMe review
Corsair Force MP600 PRO LPX 1TB NVMe PCIe 4.0 M.2 Solid State
Corsair Force Series MP600 GS review - Corsair's new mid-range SSD
Corsair Force Series MP600 GS review - Corsair's new mid-range SSD
Samsung 980 PRO PCIe 4.0 NVMe SSD Linux Performance Review - Phoronix