MacOS in generally is very buggy around SMB in my experience. Windows and Linux don't have these issues. Only android file apps in my experience are as buggy around SMB shares.
My macbook often disconnects randomly from my SMB fileserver. I ran into a bug just yesterday where the laptop client would reject re-authentification to the server after I manually disconnected from the SMB server. The only fix was to restart the macbook.
FYI, macOS Finder SMB perf is just fine as long as you connect to the SMB share by its IP address (i.e. by typing “smb://10.0.1.1” in the Cmd+K dialog.)
It’s only when you connect to an SMB share by name (incl. by browsing to the share in the Network view) that things get hinky.
I think the Finder — or discoveryd underneath — is doing some kind of non-cached(!) WINS name lookup for each fopen(2) syscall against SMB shares mounted through their WINS name.
If your SMB server is running Linux, IIRC (this was ~8 years ago, so this might no longer be true) that it also seemed to work, to run avahi on the Linux host, configured to announce the system the way you would if you were setting up AFP on the host; and to have avahi then announce SMB as a service (mDNS SRV record) for the system.
I'd recommend trying to find an old guide for setting up a Linux AFP server. You don't actually have to set up (or even install) AFP, though; just do all the avahi parts!
Why does this work? I think it's because, unlike for the WINS names underlying SMB, macOS seems to have an optimized and cached name-lookup path within discoveryd for the mDNS SRV records that would underlie AFP shares. And this code-path seems to be perfectly happy with discovering an SMB share via mDNS. (Probably because of some legacy transition Apple went through internally, where AFP shares were deprecated + replaced with SMB shares, while still being published "as if they were" AFP shares, via mDNS.)
It's not just SMB. it's nfs and iscsi too. Awful performance or downright completely buggy and broken. Iscsi requires third party software and you can enjoy the year 2006 in terms of performance. It's truly pathetic.
My macbook often disconnects randomly from my SMB fileserver. I ran into a bug just yesterday where the laptop client would reject re-authentification to the server after I manually disconnected from the SMB server. The only fix was to restart the macbook.