Why are the UE4 updates (from the launcher) SO big?

Every update is over 1.5GB… Is it downloading the entire engine again, or just patching the files that have been modified?

I’m on a very slow internet connection (1Mbps download) so it takes hours for me to download the hotfixes. I know that building from source would probably save download time for small patches, but my computer is also very slow so it would take even longer to build it.


I believe it’s just patching over the files that have been modified because last I recall (I rarely pay attention to actual download sizes these days) the default size is approximately 6GB.

Ah. That must be a lot of files then :stuck_out_tongue:

Because Unreal does not have delta updates, it always patches all (ie. downloads and replaces all the files).

My connection is fast… But I’m under a limited monthly data plan and such updates hurts a lot yep.

It patches over everything because of stability reasons. They test on their end and things normally work, so they move them over to us, as the original files, in hopes of getting the best and stable result possible. It’s a lot easier for them.

The culprit is PDB I guess, even a few liners C++ changes will result in massive GB update.

Thanks for your replies, it’s a shame they’re so big but I guess we can’t have everything. It’s a great engine though so it’s worth it. Loving using it so far.

This launcher is painfully slow updating/installing things, I imagine all of this is partially why. I love how in the middle of installing an update it hangs at anywhere from 87-93% and stays there for hours on end. Meanwhile, my task manager is telling me I’m only using 50% of my available resources, but I’m literally unable to do anything else on my computer- else, everything freezes.

I just wasted 8 hours downloading and installing 4.14. It’s still not installed. I feel like I’ve been stuck behind an old couple driving all day. I had many more things I wanted to do today. I’m sorry if this comes off harsh, it could be a bit emotionally charged… but please, dudes at Epic- fix this slow POS launcher, for the love of god. Thanks!

seriously trying to install 4.14 for the fourth time today. going crazy over here.

If it hangs after 80-something, then it is after it has downloaded stuff. Have you tried disabling firewalls/antiviruses for the duration of installation? I’ve been in a similar situation to you, where it progressed at a snail’s pace, until I noticed AV was using 40% of CPU and disabled it. Ended within 10 minutes.

This is usually the case when the launcher is installing dependencies.
If you pay close attention, it goes from downloading to installing and then continues to download…
Depending what is installed, it may seem that the machine hangs.
My system is unresponsive too during every little occasional C++Redistributable installation/update…