Slow network file transfer from Apple to Windows

The solution below worked for us.    (We disabled NetDMA) – This also correct copy problems to a NAS that runs a Linux based OS.

To enable or disable NetDMA, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. Locate the following registry subkey, and then click it:HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters
3. Double-click the EnableTCPA registry entry.Note If this registry entry does not exist, right-click Parameters, point to New, click DWORD Value, type EnableTCPA, and then press ENTER.
4. To enable NetDMA, type 1 in the Value data box, and then click OK.
5. To disable NetDMA, type 0 in the Value data box, and then click OK.
6. If the EnableTCPA registry entry does not exist, enable the NetDMA functionality.

Remember, you may also need to adjust your network card from Auto to a manual setting.   (Try this on the Apple and/or the Windows Computer)  When computers handshake (exchange data) autosense does not always work.

How to adjust Windows NIC cards – Link

For Apple  -System Preferences” – “Network” – ” Advanced” – “Ethernet”

Our theory is - “Network speed tweaking is an art and never a science”