Previous post here is locked so I can't reply to it, unfortunately, and mod marked post as solution that wasn't.
PXE works great with legacy boot options, but when booting with BIOS set up for UEFI, it takes a crazy amount of time to PXE boot, so much so I give up on it.
I'm following up on this issue and see some SCCM users were able to work around it my modifying TFTP block size and/or disable dynamic window size.
Is this something that can be adjusted when booting to PXE using Symantec Deployment/Management/Altiris?
From VMWare forum"our solution was to set a fixed value for TFTP blocksize at the PXE-Server und disable dynamic window size. "
From reddit comment"I'm on 1610 and I've adjusted the Block\Window size settings. I based my testing on the ccmexec post and I also have a variety of models as well including: Dell, Lenovo, and HP. I have mine set at:
TFTP Block Size: 400 TFTP Windows Size: 8
and that sped up a 5 minute download to about a minute. I couldn't go any higher because of our HP Probooks. Give that shot and see what happens."