What PCIe generation does the Lenovo ThinkCentre M70q Gen 3 use for its NVMe slot?

The Lenovo ThinkCentre M70q Gen 3 jumps to PCIe Gen 4 for its NVMe slot, a noticeable step up from its predecessor. It still has the same two-drive layout (one M.2 2280 slot and one 2.5-inch SATA bay with a 7mm height limit), but the faster bus means snappier SSD throughput for the primary drive.