I have a NanoPC T4 (RK3399) with Friendly ARM ubuntu distro NOT Armbian as yet - I plan to migrate hence why I am reading these forums
If this provides a data point?
scott@hass:~$ sudo lspci -vv | grep -E 'PCI bridge|LnkCap'
00:00.0 PCI bridge: Fuzhou Rockchip Electronics Co., Ltd Device 0100 (prog-if 00 [Normal decode])
LnkCap: Port #0, Speed 5GT/s, Width x4, ASPM L1, Exit Latency L0s <256ns, L1 <8us
LnkCap: Port #0, Speed 8GT/s, Width x4, ASPM L1, Exit Latency L0s unlimited, L1 <64us
scott@hass:~$ sudo hdparm -t /dev/nvme0n1p2
Timing buffered disk reads: 1784 MB in 3.00 seconds = 594.26 MB/sec