If that's the setup, the only way anything would run more than 1Gb is if the Synology is doing SMB-multichannel (which if they setup 4x1Gb LAG, then it's not SM

If that's the setup, the only way anything would run more than 1Gb is if the Synology is doing SMB-multichannel (which if they setup 4x1Gb LAG, then it's not SMB-MC). [edit] reading the article, they do have the Syno setup for SMB-MC and that's the only reason this wasn't stuck at ~120MB/s