M1 Mac Mini very slow file transfer to Freenas SMB
I have a new 2020 M1 Mac Mini. I use Freenas running on a separate server for Time Machine backups and media storage (pictures and videos only). The entire network in between is gigabit switches with CAT 5e cabling.
The problem I'm having is that transferring large files TO an SMB share on the Freenas server is EXTREMELY slow. I have a 40GB file to transfer (my wife's photo library) and it appears it will take ~2-3 days. It is running at well less than 100 Mbps, I would say more like 5-10 Mbps. I have the same issue when I try using Wifi instead of ethernet, and when I replace the Mini with my 2020 Mackbook Pro (Intel) using the same ethernet connection, the transfer speed is normal. So I don't think the problem is the network, it appears to be limited to my Mac Mini.
Also, when transferring files FROM the Freenas to the Mini the speed is normal. The problem seems limited to transferring files TO the Freenas SMB share from the Mac Mini. Any thoughts?