When downloading games via Galaxy, it seems that it downloads the uncompressed files of every games, meaning that the download sizes are much bigger than if you downloaded the manual installer.

For example last night I downloaded Pillars of Eternity on Galaxy, and the entire download size was 20 GB! While if I downloaded the installer it would only be 3.9 GB for the main game and 2.3 GB for the expansion.

Will Galaxy ever use compression for downloads like how Steam does? Is it something they plan to add?

What makes it even worse is that many games on Galaxy when they get a patch redownload the entire game. For example right now I got an update for Kyn which was 8 GB in total.

Please do something about this GOG, it is so incredibly wasteful.

Yes. Downloading compressed files is on the list of things to do.

Uncompressed files is a bit easier to maintain/update, and it is often used while still in testing, since it's easier to update one file instead of the whole archive. The problems arise when you have a list of files that any of which could have been modified, and you have to download the modified files only. So you need an on-the-fly compression method that can compress and send only the required files, and not everything again. I think such methods exist, but they do need proper implementation.

I completely agree with this. ^

You aren't the first to complain about that and you certainly won't be the last. I brought that issue up during the alpha and got the reply that compression is a planned feature. But they didn't know when it will be ready.

^ This

Because it's in "beta" so Gog just makes up things as they go.

o-
Yeah, that's the real stinker. Having several downloads in the 5-10GB range lined up every time I fire the damn thing is NOT cute. Especially on my family home computer, with its 900MB per hour internet...

For me, it's the main reason I don't use Galaxy anymore : It actively punishes you for having several GOG games installed on your computer.

You know, a while ago (8 years?) i recall writing some compression code for AHK, more specifically it plugged into the zlib.dll file letting me use those compression routines. One of the things you could do was include a dictionary. With the dictionary known, you can compress a huge file that has large portions of identical properties, and they come out as only a few offset/length codes. Using that in mind, with the known version (with no changes to the files) you could send compressed versions of ALL files, and only the ones that changed will fail on the compression and send large chunks of data...

I recall taking a document, then treating the entire document as a dictionary, then compressed the identical document.. The result was... 20 bytes big? (We're talking 100k document so it wasn't tiny).

I think there was already an explanation about this. Forgot in what thread.

Edit: found it. From the blue one.

I'll just quote it here :

"Yes, we plan on having the downloaded files compressed as well as hope to additionally introduce delta updating for the patching in Galaxy. Both should ultimately lead to even smaller updates than standalone ones on the website. However this is not something we're ready to talk about yet in details but it's definitely on the list."

Agreed, for me it's one of the big reasons why I always set games to manual update, and just don't let it update those I'm not playing. Having the blue dot to notify me of updates when I want to start is still nicer than tracking updates manually.

Even with precautions, Galaxy still managed to bite me. I imported Blackguards I had installed long before. Just to see what will happen, didn't even intend to play it. Galaxy insisted on downloading 20G of data... and in the process, it apparently managed to break through my data limit, so now I have to live with crappy 900kB/s connection until the end of month. Didn't even know I HAD data limit, TOS of my provider specifically says they don't employ such measures at this time. Guess it is outdated TOS. I wouldn't mind the data speed, but it apparently comes with enhanced lag too.

Sorry, just ranting a bit. Compression and download_only_what_has_changed (even on file level for a start, doesn't have to be binary delta patches), would be much welcome.

Pushing Galaxy down their user base throat (and especially to their new users) without having this kind of basic functionalities kinda boggles the mind. I know they wanted to launch it in time for TW3, but holy crap, what were they thinking? Oo'

Well, we only got the pause download capability yesterday...

It's probably one of the top features on the list and most probably currently the top men of GOG are on it.

I suggest not to use Galaxy until it downloads compressed files if you do not have really incredible high speed internet. I mean, why waiting really long if it's not needed. One could see it as a showstopper.

I'm asking this myself. Better to finish the basic functionality (compressed, pausable downloads) before starting to work on optional features (e.g. adding friends). But not with GOG. What were they thinking? Who is in charge there?

High internet speed isn't the problem, data caps are. You can play while Galaxy is downloading files, and it will update when you stop playing. But if you have a data cap, the updates will chew a big part of it.

Again, compression of files (especially on a system that supports rollback) is a pain. You need to be able to check and deliver an arbitrary number of files for the repair option, while still being able to compress them. So you need a system that compress and transmits on the fly, or an absurd amount of space for the compressed files.
So no, you first make sure you have the delivery correct, then go for the features people ask (Why is adding friends so hard? Ricky?), then work on optimizing the existing features. Compression will come, but it will be a pain to get it right.

Well, I don't have a data cap, but having my household internet completely clogged for 10 hours every time there is a Dreamfall : Chapter update (9GB, and episodic, so it updates pretty often) is a problem. And that's just 1 game. I have over 20 GOG games installed on my laptop, half of them pretty recent.