I followed your test with my notebook (Intel i5 (11th gen), Windows 11 23H2, Intel NVMe SSD 500MB) and used a WD My Passport Ultra 4 TB external HDD on a USB 3.2 port.

2. took about 14-15 minutes
3. I used 7z to create the zip file
5. With 7z it took 62 seconds.

Update: For a lark, I've given InnoExtract a whirl for (original) Quake, and I've got to say, this was so much nicer to see that I'm not sure why this isn't the default method. Most people are going to throw Quake at a source port (myself included), so why not?

Wow, that's quite the difference and there's definitely something going on there. Either it's single-threaded or the extra stage in the offline installer having to lookup a Galaxy manifest to figure out what the real name of every file (stored as something like "tmp/bf/1c/bf1c5c56422645f9d4500140c2460ed1") is then rename them one by one, is slowing it down vs if the installer were a normal self-extracting zip. Some people have rebuilt their own GOG installers using the same InnoSetup as what GOG uses to build their installers and it's still faster. Certainly 15 vs 1 minute time disparity to move the same number & size of files across the same discs is more than what adding registry entries (barely adds +1-2 seconds) or installing bundled VCRedists (usually adds +5-10s) takes.

The file setup_civilization4_complete_2.0.0.4-1.bin is a 3 GB rar file. I tried WinRAR to extract only this bin file and it took 75 seconds. Inside you have the folders DirectXpackage, game, support, __unpacker.

No, it cannot since the blocking call in the main thread is there as a DRM-measure in the first place. Remember that GOG's convoluted thingy is there to replace Steam dependency without recompilation or at least without modifications to the game's code.

You seem to miss the reason why GOG's wrapper exists.

Well, there is no telling until (if and when) they change Civ IV to the new format... It could just as well be due to the big number of small files.

Well, at least it does install, even if it takes 11 minutes for a mere 3GB installer.

Do I read it right it took you over 2 hours to install Civ IV? Wow, that is indeed something.

I guess most of that is then due to Wine and/or external hard drive... but still, even at 11 minutes that I got (installing locally on an internal SSD), it still was quite slow for a 3GB installer. Possibly due to the high number of small files in the game.

Odd that it still took longer for me (11 minutes) on a relatively powerful gaming laptop (Windows 11), installing within the same SSD (the installer was copied to the SSD to which I also installed it). I didn't even have a HDD slowing things down.

I'm actually glad that the Civ 4 setup.exe turned out to be a very old (and borked) installer. Yes, it is horribly inefficent in extracting by itself, but it can be opened by any capable tool instead because the bin-file is a clean RAR archive. I see no purpose in further investigations or worrying about benchmark results. The "stream format" thingy was a red herring. GOG's new installer format has been acquitted, at least for now. ;-)

DRM protection that can be circumvented by waiting < 20 seconds? Are you joking?

And for like the 3rd time it's the developer's choice to wait. You do not EVER have to wait on a blocking call. If you do, you are choosing to. It's also the developer's choice to continue the program despite galaxy being found or not.

You are acting like the developer has no control. That's just not the case.

To quote your words: Are you joking?

You clearly don't understand and don't care to research what you are talking about.

The timeout is in GOG's fake Steam dll. After the timeout has happened (waiting for Galaxy) that fake Steam DLL continues to work and in turn pretends Steam is running and that the game is owned. That's the way the (not hard) Steam is running DRM is circumvented. GOG's DLL is a crack. Of course you make a DRM call however soft/hard it may be with a blocking call. Everything else would be pointless.

As I wrote before, GOG claims to have a drop in API/ABI-compatible replacement to get rid of Steam dependency without reworking your game at all. And that is not true if GOG's DLL has a timeout that the original is not supposed to have.

Of course the develops have control, but they thing the gain is not worth the effort. Don't put words in my mouth! That's what you can read (almost) every time a GOG release is discussed. If the developers really cared, they wouldn't use the wrapper at all, but that would obviously be a lot more work that most people are unfortunately not willing to take on. So in most cases it's either a half-baked rework or nothing.

And what you still don't understand (or as I think pretend to not understand) is that the games in question doe not know anything about Galaxy at all. They think they are talking to Steam via the usual DLL calls.

After seeing your posts on many different Threads I'm convinced that you are neither interested in a fact-based discussion nor do you know anything about the things that you claim to be an authority about at all.

I have a folder of save files backup. So I agree with you 100%, but we all know people will give up freedom for convenience.

Especially since I've often read about cloud save functionality accidentally resetting progress by conveniently restoring an older version of a save or even a completely broken one.

I have a save file backup folder and a script that creates an automatic backup archive if the save data has changed on startup of notoriously buggy games that don't allow multiple saves and are likely to break that one save like Lego Harry Potter 1.

Bingo. The DEVS choose how the program works. It is totally in their power to deal with it. They chose not to.
All the rest is just noise.