Yes, they've indicated many times in the past that they plan on implementing delta updating and compression, it just has not been completed and rolled out in the beta client yet. I'm surprised they're not using on the fly compression though via rsync or some other pre-existing mechanism that is open source as it's a freebie.

In the mean time, I only install the smallest of games directly with Galaxy, generally games that are under 1GB installed. Anything bigger than that, I install from the standalone backup installers as it is extremely faster. Mind you, updating can be slow for newer games like The Witcher 3 with its 2GB updates unless one disables auto-update and handles updates manually via backup downloads too.

I hope the next major release adds compression at least if not deltas also.

Sometimes I want to play exactly one single game and then I don't want to wait longer than necessary. Waiting several hours or waiting less than one hour is a big difference.

Anyone ever heard of zip? There is a nice library zlib which supports compression on the fly, probably since 1995. Also several FTP programms are using this technique.

All in all I think that small downloads is a core feature and deserves top-most attention. It is much more important than many other things GOG has been working on with Galaxy and I think they seriously make big mistakes here and come across as a bit incompetent (in my eyes).

So what's stopping you from playing? GOG games don't need to update before you can play, at least from what I recall, and you should be able to play while Galaxy is downloading files.

And that is most likely what they will end up using, once they've made sure that they got the file delivery going correctly. Make sure you are delivering the correct files first, then optimize the delivery.

And killing internet for every single person in the household for 20 hours, unless you manually (and messily, Galaxy doesn't like it and cries like a baby when I do that) disable every single download in the queue (in which case the whole downloading mess will be for the next session.)

I know, pausing the DLs and incremental patching are coming. But rolling out Galaxy in its current featureless state feels pretty stupid.

I'm reminded of looking through the hardware options, and there would be data compression for modems, how many bits to use for error detection, speed options, etc.

Also if performance is a big question, there's ZLO if memory serves me right... takes almost no time at all to offer compression.

They are free to do it any way they want but I won't use it until they finished optimizing the delivery. For me this is one of the core points. The absence of the optimization not very useful to me. Also my impression is that they lack focus.

And indeed I'm still using the GOG downloader and I'm happy with it.

Ditto...

Update:
I was wrong! Downloads in Galaxy are compressed. Please disregard the old post below.

Old post:
This topic is from 2015. Not it's 2021. I just downloaded a game in Galaxy (Metro Last Light Redux) and it's downloading 8.5GBs of data instead of 4GB.

Have they abandoned their plans to compress downloads? I have a 100GB per month cap on my connection. Also, downloads take much more time than needed. Steam for example downloads games at least twice as fast compared to GOG. If I have to wait for two hours for a game to download in GOG, Steam will download the same game in 1 hour or less. This is a huge deficit in GOG Galaxy :-/

Where are you getting 4GB from? The standalone installer is the same size as Galaxy around 8.5 GB. Compression was added to Galaxy a long time ago.

yes, that's indeed how it works.
if you don't believe it, look at the source code of lgogdownloader ;)
the galaxy api only delivers compressed data.

I don't know if (or where) galaxy temporarily stores the compressed data, or if they decompress the data on the fly as it arrives.

^This. Nowadays the Galaxy downloads are usually (a bit) smaller than offline installers.

You are right! I was wrong. Not sure how I got confused, but I somehow thought the offline installer is 4GB. It's not.

Nothing to see here, move along...

I'm really not familiar with 'lgogdownloader' ... and I'd likely not be able to understand the source code or the API entry ... hence why I have only done Windows based GUIs for programs built by others who do understand.

My interpretation, going by your claim for 'lgogdownloader', is that it is more like Galaxy for Linux, than like 'gogrepo.py' or 'gogcli.exe', that only work with the Offline Installers. Is that correct?

Shame, I'd really like to know, to double check this.

The only other way to double check this, would be doing some kind of download comparison.

In any case, as I have said elsewhere, a Galaxy download and install takes much longer than just downloading the Offline Installer files, hogging your bandwidth and time taken to download the game overall. Of course I realize you aren't installing the Offline Installer files, but I am just referring to actual download time for a game. If Galaxy is doing a bit of each, as you claim, it is doing a repeat of download & install (extract) for every file ... so taking much longer downloading overall due to the install part of the process. EDIT - Or perhaps, the files are stored compressed at GOG, but extracted as they are being downloaded ... which would really make them not compressed downloads ... and taking longer to download.

My belief is, sooner downloaded is best ... especially if you have a flaky connection.

I wonder why that might be?

I would have thought each compressed file has its own overhead, so less files (as in Offline Installer files) would mean less overhead.

I see that as a bit like a package or bucket for each file. Surely those extra buckets or packages add to the size.

i.e. 555 file packages downloaded by Galaxy, as opposed to 2 file packages (EXE + BIN) for the Offline Installer files.

And of course, that is being conservative. Bigger games have far more of each.

no, lgogdownloader is a simple commandline tool like gogrepo.
But it allows you to download offline installers and download game data directly from galaxy repositories.

we live in the golden age of multi-threading/multi-processing ;)
stuff like downloading, decompression and write to disk can happen simultaneously.

that being said, I have don't have much experience with Galaxy nor did I ever measure download times so I can't really comment on if or why it would be slower.

since the offline installers nowadays are built by shoving the data from the galaxy repositories as is into inno setup, I would expect the size to be pretty much the same.
the only difference I can think of is that the offline installers often include 3rd party requirements, like .NET, vc runtime or stuff like scummvm. I would assume that Galaxy handles these separately, so you don't have to download them with every game again.