[ilyt]

> For example, AMD CPUs have a lot of lanes, but unless you have an EPYC, most of them are not exposed, so the PCH tries to spread its meager set among the devices connected to your PCI bus, and if you have a x16 GPU, but also a WIFI adapter, a WWAN card and a few identical NVMe, you may find only of the NVMe benchmarks at the throughput you expect.

example from my X670E board

* first NVME = 4x gen 5

* second= 4x gen 4

* 2 USB ports connected to CPU (10/5 Gbit)

and EVERYTHING ELSE goes thru 4x gen 4 PCIE bus, including additional 3x nvme, 7 SATA ports, a bunch of USBs, few 1x PCIE ports, network, etc.