The upgrade can be a lot faster w/o 3rd party antivirus. I did several attempts upgrading from 23H2 to 24H2 for an unrelated problem (2 incompatible/buggy "drivers" or features that were leaving a "trace" in the Panther folder, but difficult to detect, so I did several "general cleaning" ops before detecting it, among them uninstalling my 3rd party FW/AV). With the FW/AV the update was taking like 16 hours (it failed in the very last phase), after uninstalling it took like 2 hours. The computer (in my sign) is slow.
In this and other computers I've noticed that some ops that require working with WIMs (like building booting medias) are a lot slower with 3rd party FW/AV (from like 5 minutes to like 40 minutes).
There's a reason for this: the 3rd party FW/AV checks every file produced including intermediary ones, and the said works produce them by the hundreds or thousands.
Other "lighter" works like producing a compressed file (provided it doesn't have a massive amount of files, I suppose) get smaller delays. A typical work in my computers (not in the W11 one of my sign, where I have uninstalled the program to increase performance and b/c the latest OS version has better security) goes from like 50 seconds to 70 seconds. I use "old technology" disks, like SATA SSDs or HDDs, b/c these computers are old. For the same reason they aren't powerful processors/memory either. I don't totally trust modern NVMe disks in speed, sometimes they have fast caches but the underlying storage isn't very fast.
