We've run into a weird issue today when copying files from a Windows Server 2008 R2 (SP1) to a Windows 7 Prof. client. If I initiate the transfer from the Server 2008 box I'll get 80-100MB/sec which seems to be what I'm expecting.
As soon as I initiate the transfer from the Windows 7 client end then I'm getting speeds closer to 40-45MB/sec. We've created a Ramdisk to avoid seeing limitations from the local storage for the tests. This was consistent over multiple runs.
The test file is about 3GB in size.
I also don't think that it should be related to caching. I created the files with different sizes for every run to be sure that I'm not seeing any caching effects.
Any explanation for that?
Thank you,
Felix
Best Answer
You might be seeing some effects of a slowdown due to SMB NOTIFY calls which induce transmission delays when using Windows Explorer to display the remote directory's contents while copying. You might try using a different copy tool without involving Explorer altogether (xcopy, robocopy) or closing the Explorer remote directory window after starting the copy process.