This is a direct quote from Fitgirl, an expert in data compression.

"Why GOG Offline Installers Suck"

"GOG is a great company, with some problems here and there, but they try to follow the DRM-free path they have chosen. But there is one little fucking problem, which makes me fucking mad.

GOG, your offline installers SUCK. And your engineer(s), who’s responsible for them should be fired, then hanged, then burnt (order can be changed).

So, why do they suck you may ask? Around 2-3 years ago GOG switched from old installers, which have been using RAR archives as containers to a new scheme. And it’s fucking abysmal. Lemme tell you how it works.

So, while preparing data for their installers, GOG do the following:

Every game game file is splitted to a relatively small chunks of data
Every chunk is compressed with ZLIB algo (the same which used in generic ZIP archives)
Every chunk’s name is hashed/randomized and then put into INNO Setup container with another ZLIB compression over. This stage alone is crazy – you can’t compress compressed data, only make it larger.
INNO container is splitted to relatively large BIN files of ~ DVD size.

So if you think it wasn’t crazy enough (compared to RAR compression), hear how their installers behave on your PC.

Each chunk is copied to your user temp folder (usually it’s located on a system drive, which now is often and SSD with a limited lifetime and size)
Every chunk is unpacked and then concatenated into a single original file
AFTER that this new file is copied to the destination folder from that temporary folder

So, if your system drive is small, you won’t be able to install a GOG game. You will see “not enough free space” only because fucking idiots in GOG don’t know how to make modern installers which don’t use temp folders and can decompress data directly from source to destination. Every pirated scene setup is better than GOG. They all use FreeArc-created archives with very fast yet relatively good compression, which installs faster than you HDD can process. NOT the case of GOG installers, which can be as slow as fuck. Can you imagine, that even their old RAR installers were much faster and smaller due to usage of solid compression option and direct decompression?

If you’re a victim of their installers, there is a fucked-up “workaround” for that. But seriously, changing Windows variables or using junction points to another drive only because GOG engineers get they salary for nothing? Sheesh."

Hmm, interesting read.
GOG and CDPR by extension are under a lot of scrutiny lately, maybe it's time to change some things, eh?

Interesting insights. Must be the same dudes, that re-designed the website and put news on the bottom.

We were discussing this literally yesterday on the other thread (new posts at the bottom):-
https://www.gog.com/forum/general/offline_game_installers_why_use_ctemp

Aside from an overly-convoluted packing method, some games are split between language and others aren't. Eg, Cyberpunk 2077 "needs" a +100GB size installer to install a 60GB game due to every language being included. Likewise as I gave the example in the other thread, Prey (2017) has a 24.5GB offline installer for same reason. But if you install Prey and then delete unwanted secondary languages and zip the game folder up yourself, it instantly shrinks down to 16.8GB or 2/3 of the size.

It would definitely benefit both GOG (reduced server bandwidth) and gamer (reduced backup space / download time) alike to optimise these a bit better. And as described on the other thread, the messy "thousands of files with gibberish MD5-style filenames" is the way it is because of Galaxy (the offline installers contain 'Galaxy-style chunks' of data instead of files, and part of the installation involves reconstructing them into files). This is partly why they are slower than they used to be.

Yeah, I'm one of those that needed to change my temp folder variable because of seriously low space. Not only kept that fecking Windows "saving" files in temp folders, I couldn't install GOG games. Sure, changing that variable is easy enough, but shouldn't be necessary and isn't an option for everyone. And, they made it harder for Linux users to simply extract the files without running the installer.

I've said it before - I actually prefer repackers because of this nonsense GOG are doing. Same with CyberPunk 2077 and how Galaxy/offline files are created (not automatically as they said it would be?)... what are they seriously thinking with? Everything they touch is an engineering disaster! Not sure if going Agile will be so much better unless they get someone else inn.

All those tiny files is actually a lot slower than having them in their original sizes also.

I just hate it when people insist on taking these convoluted steps and essentially makes it worse for the users because it's supposed to "solve" an imaginary problem...

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In testing I also discovered that 7zip, when using the manager and dumping the files, it would use the temp folder and then copy it to where I dumped it to. Whereas using right-click and extract here would dump it directly. But I digress...
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Well, there's a really simple fix, for me...

Bring back the old and trusty GOG Downloader!

This has literally zero impact on anything being discussed.

Still, it's true. With the old GOG Downloader we hadn't this kind of issue; it wasn't a perfect tool but it worked very well.

While we are talking about a sushi chef, you're actually talking about his driver...

Marvelous!

Some notes as a Linux user:
* On some systems, /tmp is a tmpfs filesystem, which is stored in RAM (with the possibility of files (or parts of them) being swapped to disk). An installer of this sort would not work on such a system (without workarounds, of which there are some, like mounting over /tmp in an unshared mount namespace).
* I believe that Linux installers are different, and use some open source solution (I believe it's something like MojoSetup), so they don't have the same issue that Windows installers do.
* The situation of using the Windows installer via WINE when the OS disk is small is actually better than the situation on real Windows. Typically a wine prefix will be stored on a drive that's big enough to handle games, and what the installer sees as the temporary directory is part of that prefix, so the files will be unpacked there. Hence, the free space needed for the installer needs to be on the drive the wine prefix is installed, not on the OS drive. (Also, symbolic links are a more practical solution, as anyone with decent Linux command line experience will know about them (including the "ln" command), and from what I understand they work at a lower level than their Windows counterpart. The downloader would not help here. It would make it easier to download the installer, but said installer would still have the exact same issues. People are reporting that simply patching CP2077 requires on the order of 350GB of storage space, which is absurd (neither of my laptops *has* that much space total, and neither does my Raspberry Pi (not that I would even attempt to run the game on such a low-power device); the only computer I have that would be able to handle this would be my desktop).

This is speculation on my part, but I presume this change of the offline installer format is so that they can automate the creation of the offline installers, directly from the existing Galaxy-downloadable versions. I guess that could be considered as a benefit, it if helps (in the future) the offline installers to stay on the same patch level as the Galaxy versions of games.

If the GOG download servers already have those partial file chunks (named after on their md5 checksums, not "random" names), then I guess from GOG's point of view the most straightforward, fastest and least error-prone automated method is to just take all those already compressed chunks, put them together, and then divide it to downloadable 4GB files.

I don't think it is a secret that GOG isn't really concentrating on the offline installers anymore, but they are merely an extra service, a by-product, on top of the "Galaxy versions" of GOG games. Whatever, as long as they offer those offline installers, I'm (relatively) happy. Could be worse, I guess. I personally am more annoyed that now some offline installers contain all the different language versions in the same installer because that just wastes space on my archival HDDs (for language versions I am not interested in), but I digress...

I personally am not concerned that it causes "extra stress" to SSDs when it decompresses and copies around the files more than once, as installing GOG games (or any games) is not a daily thing for me anyway. I might install some new game maybe once every two weeks, if even so often. I guess it sucks that it takes a longer time now, but I'll go get a cup of coffee and jerk off in the meantime.

If people are concerned about their SSD's longevity due to installing GOG games, go buy one of these babies:

https://www.youtube.com/watch?v=pVxTEbv1Do8

22 PETABYTE lifetime write rating, baby! You can keep writing to them for the rest of your life, and they'll just last.

The only people who should be concerned about their SSD longevity are the poor Apple M1 owners whose SSDs are soldered to the motherboard. Blame Apple!

EDIT: Well, ok, the fact that Linux gamers have to go through extra hoops to get to the actual game files in those new installers is certainly a bummer... but as long as there is a way...

Sure, an expert for releasing pirated content .

Something like the "tar" program on unix-like systems would work better for this. Most tar files you find on the internet are compressed (hence extensions like .tar.gz), but there's no reason they have to be, and when the data is already compressed a plain .tar file would work.

By the way, on such systems the "split" program can be used to split the files, and the "cat" program will re-assemble them. (Most Linux command line users know about "cat", but they might not know about using it in this fashion, and "split" is not used as much, so it isn't as well known.)

Fortunately:
* The installers work in WINE.
* Apparently, recent versions of innoextract can re-assemble the files from GOG's installers.
* I don't think the Linux installers are affected by this.

Probably this makes that person even more an expert.

This is an expretise by an expert in polite behaviour:

Fitgirl seems to be a person about whose insights I could not care less, as her hate disqualifys her as an interlocuter.

Best regards

phil