Nfsd question

Hi, Everyone

My server configuration is 2xAMD 7713, 1T memory, 24nvme 7.68T (2vdev, 11 raidz-2 and 1 hotspare), 100G network adpater, only use NFS service.

Now I am using DD for test the r/w speed, from another server with 100G ethernet adapter, I opened four sessions with dd if=/dev/zero of=/ssd2/testfile3 bs=1G count=200

But only one nfsd is reponding the the four session requests, and the maximum write speed is less than 1.5GiB. is this correct? I would think my all nvme ssd vdev could get more r/w io.

I set nfsd number of servers to 256 or 128, seems no change.

when i use truenas scale, I can see several nfsd responding, all cpu is responding rather than a few cores is peaking, so not sure if there is any configuration i missed?

anyone please kindly help.