Is PCIE x4 bootable for NVMe SSD under Linux

[Bullet64]

Ayufan Image 0.6.52

Code:

rock64@rockpro64:~$ lspci
00:00.0 PCI bridge: Rockchip Inc. RK3399 PCI Express Root Port Device 0100
01:00.0 Non-Volatile memory controller: Samsung Electronics Co Ltd NVMe SSD Controller SM961/PM961

Code:

Disk /dev/nvme0n1: 232.9 GiB, 250059350016 bytes, 488397168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Code:

rock64@rockpro64:/mnt$ sudo dd if=/dev/zero of=sd.img bs=1M count=4096 conv=fdatasync
4096+0 records in
4096+0 records out
4294967296 bytes (4.3 GB, 4.0 GiB) copied, 11.795 s, 364 MB/s

Only x2 atm. But it works   Thanks Ayufan!!