Can someone explain to me why do I need to download 27Gb for 1.06 patch in GoG client while Steam version gets 1Gb update?
This update takes so long time to download and install I am starting to believe just reinstalling the game would be faster and easier.

doesn't make sense. the offline update package for v1.05 > v1.06 is only ~538MB.

At first it did show only ~500mb. Then it was 1.5 Gb. Now at 56% update progress it is 27Gb.

Sounds like your install is booked somehow. It almost certainly would be faster to reinstall. Not sure what triggered this unless you have a major mod installed.

You're not downloading 27 gb. You download only 538 megabytes.

What's causing the holdup is that for some reason either GoG or CDPR (which for all extensive purposes is the same thing) has decided that when it patches it needs to make a temporary copy of your game, then patch the game with the download, then delete the temporary files.

No idea why it does this, but yes it's been figured out with previous patches that if you have a super fast download and slower cpu, it is almost (but not quite) quicker to redownload the game vs how they do it.

There's no real way to fix it. You just have to be patient.

I know about this thing with temporary copy. But I were checking task manager every time during the update and GoG was downloading something besides moving around files on my disk

I'm updating to 1.067 as I type this and it's only 509mb.

GOG Galaxy verifies the current files, and replaces any that get corrupted.

Example
There's an underwear remover mod that edits a single byte in one of the archives.
Offline installer fails to replace this archive, and just makes a log entry stating the file wasn't updated.
Galaxy verifies the files with each update, and gets an error for this archive, and redownloads it.

So if your files got corrupted, or you modded them, Galaxy fixes it automatically.

Well updating from 1.04 to 1.06 is a 54 GIG download for me. So I am over 130 GIG download for this game. Perhaps it will run, but it really didn't in 1.04 (Windows 7-64 here).

I'm having the exact same situation on both PCs that the game is installed to. V1.06 shows up as a 54GB update instead of being only a few hundred MB. I already had to uninstall and reinstall twice on one PC just to get the updated versions. The other I just haven't bothered with since I have a data cap (which I already paid to extend this month) and having to redownload 50+ GB every time there's an update is not sustainable.

If this is an issue with the way GOG handles updates to the game, as was stated above, CD Projekt needs to change how games are updated on GOG Galaxy as soon as possible. I would have refunded and got the Steam version instead, but I bought the "physical" edition, so the download code can't be returned.

Hey all

I really get angry. I started the update in Galaxy. It showed that around 580 MB have to be downloaded.
As others already mentioned, it downloaded much more.

But more: the update is now standing at 91% - AFTER 3 HOURS!!!

Seriously, this is NOT ACCEPTABLE!

I ask for instant change of the update code.

ha ha ha, "I ask for instant change of the update code" what a clown..... Maybe get a better internet connection, sounds like you have one of those $19.99 a month deals. I downloaded the 500 mb in 30 sec and I never saw this 27 gb thing you seem to be getting.