July 28 2011

Slow SCCM OSD TFTP / PXE

I was having an issue with very slow download of the WinPE WIM image, the screen shows ‘Windows is loading files …’ but it takes between 7 minutes and 1 hour to load the 150mb WIM file over a 100mb link.
After spending a lot of time looking into this, and changing a lot of settings including WDS TFTP block (65536) and window size (64), the RamDiskTFTPBlockSize setting in HKEY_LOCAL_MACHINESOFTWAREwow6432nodeMicrosoftSMSPXE (http://sccm.haas.se/?p=15), the final solution involved settings on the Intel teaming settings on the PXE server:

I needed to leave Jumbo Packets disabled as the client couldn’t handle it and it failed. I increased Transmits and Receive Buffers to maximum values of 2048 and performance was dramatically increased.

Once this was changed, the WIM download was well under 1 minute!

 
 



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Posted July 28, 2011 by danovich in category "SMS / SCCM", "Windows

2 COMMENTS :

  1. By Michael on

    Hi,
    Thanks for the info but do you know what the settings are for a sccm server on a vmware nic (vmware amd pcnet adapter)?
    Thanks again!

    Reply
  2. Pingback: SCCM 2012 PXE Optimization - Workplace Vision

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