Some Macs browse the network drives very slowly. Users report delays when navigating the file share- usually evidenced by delays populating the contents of directories.
- Click on the Maginifying glass in the upper right hand corner of your Mac screen and type “Terminal” in the floating window and click on the result of the search. (Terminal.app)
- Copy the text after a. on the following line:
- defaults write com.apple.desktopservices DSDontWriteNetworkStores true
- Paste the text that you copied into the Terminal window and press Enter. (The cursor should just drop down to the next line.)
- Restart your computer.
Taken from: https://community.spiceworks.com/how_to/85131-fix-slow-access-of-windows-smb-share-from-mac-os