Network file copy speed problem
 

I have to admit this one has me stumped, so I wanted to see if anyone here has seen this, or may have an idea what may be causing the slowdown.

A picture is worth a whole page of text in describing what's happening, so I've attached an image that shows where the slowdown is occurring when moving a 3meg file around from system to system. It doesn't matter what file transfer method is used, I've tried Explorer, Robocopy, FTP, FileSync, etc.

It also doesn't matter whether I'm on #3 and copy the file over from #2, or whether I'm on #2 and copy the file over to #3. Any traffic from #2 to #3 moves at a crawl. I've tried canceling the copy once it starts and it takes the same 3 minutes or so to cancel the operation as it does to make the copy.

Checking the interface and tcp settings using 'netsh' all the settings are identical on both Win 7 systems as I expected, as everything else is working perfectly. I've been Googling and can't find anything similar, as slowdowns always affect both directions, I can't find anything regarding a slowdown in one direction only.

Anybody have any clues?
Attachment 231008

What happens if you copy 1 <--> 3, or 1 <--> 2? If the settings are the same on 2 and 3 you need to examine non-settings. Is the hardware the same?

As you can see in the image I attached the only problem is 2 > 3. Even 3 > 2 works fine. Being different PC's they are different hardware, but it doesn't appear to be a hardware issue or the slowdown would show up somewhere else as well. I would certainly expect 3 >2 to show a slowdown, since it's between the same two PC's, but it doesn't. The problem is only between two specific PC's, and then in only one direction.

So the problem is with the upload of 2. Check for the latest NIC drivers on 2, and if that doesn't work swap the network cable.

I found the problem!

Printing to the network printer was also very slow. So reads (receiving) through the NIC were fine in all cases, but writes (sending) to the other Win7 system and the printer were painfully slow. I started searching with that in mind and found the answer at answers.microsoft. I disabled "Large Send Offloads (IPv4)" in the NIC and now everything is working as it should.

A little more checking and apparently the Realtek NIC drivers turn this feature on, whereas the Broadcom NIC drivers on the other Win7 system do not, and it was disabled there. Enabling LSO on that system caused it to start acting the same with slow writes to the other Win7 system and printer, but normal read speeds.

So both are disabled now and life is good.... time for a beer.

I was just going to mention that. :rofl:

Not really. My first thought was a defective anti virus installation.

It's always something.

Iv got a client that mentioned to me that sending files to the new printer has been slow for them lately. I might have to check that out on their pc. I dont think anyone else in the office is having a problem, so I know its not the printer

http://support.microsoft.com/kb/2675785
http://support.microsoft.com/kb/829700
http://social.technet.microsoft.com/...c-ca143db9775b

Also, turning off Remote Differential Compression might help
http://www.trishtech.com/win7/turn_o..._windows_7.php