It’s possible to change the size of the blocks used for the Trivial File Transfer Protocol (TFTP) transfer; the larger the block size, the greater the performance. Microsoft’s recommendation is to not set higher than 16384; in addition, you must use multiples of 4096, such as 8192, 16384, and so on. I got a huge performance boost from using a value of 16384. Perform the following steps:
Log on to the Configuration Manager PXE Windows Deployment Services (WDS) server.
Open the registry editor (regedit.exe).
Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\SMS\DP.
From the Edit menu, select New, DWORD value.
Enter a name of RamDiskTFTPBlockSize and press Enter.
Double-click the new value.
Set the Base to Decimal and set the value (e.g., 16384).
Restart the WDS server service.