Hello,
We have recently upgraded our file server solution from a Windows XP install with shared folders. To Windows Server 2012. However, we have been seeing a noticeable difference in network speeds when opening a file on the server from a client PC.
Network transfer speeds are fine when copying files from the server to a client, (approx, 5-10 seconds for a 140Mb file). But if you try and open that file over the network. (e.g. A client PC running an installer from the shared folder on the server). The transfer speeds are painfully slow. (running the same file can take hours). I have included two images, the task manager graph showing the network activity. Comparing a file copy over a file open.
The above image is when copying a 142MB file from the server onto a client PC. Transfer took about 10 seconds. At about 660mbps.
The above image was opening the same file from the shared folder. This took approximately 3 minutes (a fast example). And averaged about 19mbps.
This problem seems to be non-existent after the server has been restarted, but gradually deteriorates as the uptime increases. Noticeable differences beginning to occur after about an hour.
The only third party software installed on this server is Symantec Endpoint Protection 12. These transfer problems persist when this software is disabled.
I have tried disabling digitally signing SMB packets according to this guide: http://jrs-s.net/2013/04/15/windows-server-2012-slow-networksmbcifs-problem/ And the problem seemed resolved for a short while. But has recently resurfaced. I have two GPOs and they both have these fixes configured in them.
Does anybody here know what the problem could be?
Thanks