I've been having an issue with a Windows 10 client experiencing very slow download speeds over SMB, but normal upload speeds.
I'm able to demonstrate this using LAN Speed Test with the following results:
As you can see, the upload speed is as expected, but the download speed is incredibly low. This test was run with the client and the server connected directly with a CAT6 cable, nothing between them at all.
I've seen some posts online discussing disabling NetDMA and modifying the TCP Chimeny settings, however none of that had any affect.
The server is a Windows Server 2008 R2 Standard, and the client is a Windows 10 Pro. Both machines have gigabit NICs. The
\Temporary share is located on a SSD, so it shouldn't be that big of a bottleneck.