PCI-E X4 to M.2/NGFF NVMe SSD - support?

[caewok]

Just got this NVME drive to work in a RockPro64:
ADATA XPG SX8200 PCIE NVME GEN3X4 M.2 2280 480GB SSD (ASX8200NP-480GT-C) W/ BLACK XPG HEATSINK 

I am using the Ubuntu minimal 18.04 ayufan image. 

With the 4.4 kernel (direct):
rock64@rockpro64:~$ sudo hdparm -tT --direct /dev/nvme0n1
/dev/nvme0n1:
Timing O_DIRECT cached reads:   1214 MB in  2.00 seconds = 606.59 MB/sec
Timing O_DIRECT disk reads: 1834 MB in  3.00 seconds = 610.76 MB/sec


4.4 kernel (from mount):
rock64@rockpro64:/mnt$ sudo hdparm -tT /dev/nvme0n1
/dev/nvme0n1:
Timing cached reads:   3006 MB in  2.00 seconds = 1503.59 MB/sec
Timing buffered disk reads: 2062 MB in  3.00 seconds = 687.12 MB/sec


4.20 kernel (direct):
rock64@rockpro64:~$ sudo hdparm -tT --direct /dev/nvme0n1
/dev/nvme0n1:
Timing O_DIRECT cached reads:   1628 MB in  2.00 seconds = 813.37 MB/sec
Timing O_DIRECT disk reads: 2996 MB in  3.00 seconds = 998.50 MB/sec
rock64@rockpro64:~$ sudo hdparm -tT /dev/nvme0n1

4.20 kernel (from mount):
/dev/nvme0n1:
Timing cached reads:   2668 MB in  2.00 seconds = 1334.56 MB/sec
Timing buffered disk reads: 2218 MB in  3.00 seconds = 738.65 MB/sec

[PsySc0rpi0n]

I have a Samsung  970 EVO Plus (NVMe M.2) 250Gb.

Operating system: Debian Bullseye
Linux rockpro64 5.10.0-4-arm64 #1 SMP Debian 5.10.19-1 (2021-03-02) aarch64 GNU/Linux
Filesystem: ext4

I got these results

Code:

$ sudo hdparm -tT --direct /dev/nvme0n1

/dev/nvme0n1:
Timing O_DIRECT cached reads:   912 MB in  2.00 seconds = 455.67 MB/sec
Timing O_DIRECT disk reads: 1368 MB in  3.00 seconds = 455.86 MB/sec

Code:

$ sudo hdparm -tT /dev/nvme0n1

/dev/nvme0n1:
Timing cached reads:   2616 MB in  2.00 seconds = 1308.43 MB/sec
Timing buffered disk reads: 1556 MB in  3.00 seconds = 518.33 MB/sec

Not sure these values are normal or not. Someone can say anything about these values?

[Cerberus]

I attempted to use a SK Hynix PC300 while booting from an SD card, but I could not get the RockPro64 to boot with the SSD installed. It boots without it.