Don't want to buy an over-spec'd NVMe; what's the max speed for an PCIe 2.0 x4 M.2 slot? : r/buildapc
PCIe Gen 4 vs. Gen 3 Slots, Speeds
GLOTRENDS M.2 PCIe NVMe 4.0/3.0 Adapter with 0.12 Inch Thick M.2 Heatsink for M.2 PCIe SSD (NVMe and AHCI), PCI-E GEN4 Full Speed, Desktop PC Installation (PA09-HS) - Newegg.com
Top 12 Technology Trends: PCIe Specification Roadmap Evolves in Tandem With Increasing Bandwidths
PCIe x4 vs x16 for single NVMe SSD speed increase? | MacRumors Forums