If you’re looking to improve the performance (quite significantly in my experience) of Trivial File Transfer Protocol/TFTP (in other words to improve the download speed of your SCCM boot images to your clients from the DP) you can add some registry keys on the server hosting the PXE-enabled Distribution Point to achieve this.
The two keys required (and the values I suggest using) are:
New-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\SMS\DP" -Name RamDiskTFTPBlockSize -PropertyType DWord -Value "16384" New-ItemProperty -Path "HKLM:\SOFTWARE\Microsoft\SMS\DP" -Name RamDiskTFTPWindowSize -PropertyType DWord -Value "8"
Once the keys have been added, restart the “Windows Deployment Service Server” service and that’s you finished. 🙂
One caveat with this change is that it can also adversely affect performance and in some cases even break PXE altogether (as I found out with my Hyper-V 2012 R2 VM’s – VM’s stopped working completely while physical hardware zipped along like shit off a stick) so some tweaking of the values may be required depending on your environment. Basically one size does not fit all with this change.
Can’t find any proper information on SCCM CB but it looks like this is a supported change from looking at this TechNet post: link
UPDATE 30/09/2016 – some much better detail and testing results for this TFTP optimisation provided by Jörgen Nilsson on the excellent ccmexec.com website – link