The server pc system is windows server 2008 R2 64bit Clients pcs have vb.net program to process images and save are on server. All 30 clients' pcs are saving the images in one folder on the server and they are reading the sources images form it. The result image file size will not be more than 200KB. If I run only 1 or 2 clients they will save every image by less than 1 second, But if I run all 30 clients; the save function will take more than 10 seconds for every image. It is normal code: bitmap.save ("\\server\test\fn.png") Any help pleases.

There are several aspects: 1. You have not noticed what operating system is in clients. 2. Incompatibility in SMB version may cause some delay. Windows XP has SMB version 1 and Windows 2008 R2 has SMB version 2.1 3. xcopy has better performance whe compared with simple copy. 4. Some network interface parameters may have impact on speed, namely QoS (If you do not use it, disable it. 5. The special chapter is switch or router. 6. If the problem is on the server side, the Performance Monitor would show for example longer queue 7. Use Network Monitor to pinpoint delays. Regards Milos

I agree with Milos. Use wireshark or MS Network monitor to understand which step in the process is causing the delay. I have a network of about 70-90 computers running a mixture xp and win 7 - reading and writing to a virtualised 2008 R2 file share. I don't see any performance issues. Also something to look at may be the server spec? Are the clients and server on the same subnet? Sravan

Thank you.. I tried these points and no usefulness: 1- Installing this MS hotfix: http://support.microsoft.com/kb/2675785 2- disabling Receive Window Auto-Tuning 3- Configure the network cardhighest Full. 4- Disabling SMB2 on the server. 5- Making another computer as server for test (windows 7 and withswitching to 56 bit encryption) No fine. Only one thing worked (fine): - Making another computer as server (windows XP 32 bit), the speed is very good!, But the problem with limiting connections. My clients systems are: Windows 7 64bit OR Windows xp 32 bit Network monitor log (30 clients working): Network activity: 100 Mb/s Send to (every client): 500kb/s Receive (every client): 20kb/s Network monitor log (2 clients (windows 7 64 bit) working only): Send to (every client): 1.5 MB/s Receive (every client): 70 kb/s Network monitor log (2 clients (windows xp 32 bit) working only): Send to (every client): 1.5 MB/s Receive (every client): 50 kb/s Help

Hello, try toggling TCP Chimney offload between on and off and see if there is a performance difference between the two.Miguel Fra / Falcon IT Services Computer & Network Support, Miami, FL Visit our Knowledgebase and Support Sharepoint Site

Hi, I suggest you can try the following steps: 1. Disable SMB2 again by editing the registry. Detail steps Run "regedit" on Windows Server 2008 based computer.Expand and locate the sub tree as follows. HKLM\System\CurrentControlSet\Services\LanmanServer\Parameters Add a new REG_DWORD key with the name of "Smb2" (without quotation mark) Value name: Smb2 Value type: REG_DWORD 0 = disabled 1 = enabled Set the value to 0 to disable SMB 2.0.Reboot the server. 2. Check whether you have enabled indexing of the offline files or not. If so, please to disable it to test the issue. 3. Modify link speed and duplex value in network adapter properties: Right click network adapter and choose properties, go to advanced tab, choose link speed& Duplex, select the value to Auto Negotiation In addition, it seems this issue is related with Windows Server 2008R2, I suggest you can to contact Server Forum for further help: http://social.technet.microsoft.com/Forums/en-US/category/windowsserver More reference, SMB2 Client Redirector Caches Explained http://technet.microsoft.com/en-us/library/ff686200(v=WS.10).aspx Windows Indexing Features http://technet.microsoft.com/en-us/library/dd744700(v=WS.10).aspx Hope it helps Vincent Wang TechNet Community Support

Thanks all I did all suggestions in this page, with no usefulness! Also I uninstall all windows features (all were installs), with no usefulness! So I formatted the system and re install same system: "windows server 2008 r2" I install all programs they were before formatting EXCEPT: - All windows features (else .NET Framework 3.5.1 and its required services) - Office 2010 - Power ISO The save speed is very nice now, less than one second. I do not know why! Thanks you very much.

Hello.. I install Office 2010 and PowerISO with no problem, so the reason mostly is some of windows features. Thanks.

You are expected to dig deeper when using network monitor. Try to mine more from log. Speed of transfer is the result of something. Without knowing more details the problem could not converge to reasonable solution soon. Regards Milos

Hi, Since the problem has been resolved after reinstalling the Windows Server 2008R2, the incorrect settings of Windows Server can also cause this issue. In addition, this issue is related with Windows Server 2008R2, I suggest you can to contact Server Forum for further help: http://social.technet.microsoft.com/Forums/en-US/category/windowsserver The reason why we recommend posting appropriately is you will get the most qualified pool of respondents, and other partners who read the forums regularly can either share their knowledge or learn from your interaction with us. Thank you for your understanding. Regards, Vincent Wang Vincent Wang TechNet Community Support