That certainly is pretty bad for Galaxy downloads.

GOG uses Fastly CDN servers at least for browser (non-Galaxy) downloads, and they appear to configured differently between each other. With the closest server to me, with browser downloads I normally get around 25 Mbytes/sec, regardless of how many download threads I have. On busy times it sometimes is slower (down to e.g. 10-15 Mbytes/sec) but occasionally I've seen it download even faster, like 35 MBytes/sec, but that usually doesn't last longer than a minute and then it slows down to 25 MBytes/sec again.

My theoretical max speed is around 75 MBytes/sec = 600 Mbits/sec, I get close to that with e.g. www.speedtest.net.

I then tried one US server that OldFatGuy uses, and I got similar speeds with it what OFG reported, 5 MBytes/sec per download thread (so if I downloaded two files at the same time, I would get 10 MBytes/sec). It clearly seemed that it was throttled to around 5 MBytes/sec per download thread, while my closest server is not.

Then one Aussie who seems to get rather poor download speeds by default tested "my" server... but apparently it didn't help at all in his case, he was still getting pretty poor speeds IIRC. Not sure what the throttling culprit there was.

I usually don't use Galaxy but I once tested with it to download and install some big game, and it seemed plenty fast for me. I don't recall how fast exactly but probably around 40-50 MBytes/sec. Offline installer downloads also seemed somewhat faster than with a browser. I think with Steam I actually got somewhat slower speeds than with Galaxy, but they were ok too.

Who knows what are all the things affecting the download speeds, but at least it appears to be the case that different GOG download servers behave differently, throttling the downloads with different criteria. Or at least so it seems to me.
I am also getting "good enough" download speeds, but unfortunately we can't use our own experiences as the norm. There are some ways to use a different download server than GOG/Fastly would like to assign to you (using the hosts file, or VPN, some claim the DNS you use may affect it too...), and testing it myself, I could easily see different GOG download servers seem to behave differently, like some clearly seem to be throttling to 5 MBytes/sec per download thread (and if you download several files at the same time, it multiplies), the one I normally use doesn't but it does seem to throttle to around 25MBytes/sec (regardlyess of the number of download threads) etc.

Those are for browser downloads, with Galaxy I also get better download speeds.

Here's another thing.

For me, while I get 35 to 40 MB/s from itch and Steam, I normally get 2 to 5 MB/s at GOG.

HOWEVER, I just downloaded The Witcher 3 here at GOG (not using Galaxy), and suddenly my speed leapt to 35 MB/s for downloading the entire game.

After that, I downloaded the Penumbra games, and was right back to 4 MB/s for each of those games.

So now my theory is that GOG provides better speeds (or servers) for the more popular games here, and lesser speeds for games that aren't downloaded so often.

Given that they use a CDN, that is highly likely. It would quite likely cache popular queries more aggressively.

More examples from today:

"Victor Vran", "Myst" (2021), and "GUN" downloaded at a steady 3 to 5 MB/s.

Immediately after that, "Obduction" downloaded steadily at between 35 to 40 MB/s.

So, for me at least, the slow download speeds seem to be title-dependent. Either GOG is favoring more popular games, or is using some other metric. Maybe the publisher gets charged less if they agree to have their game in the slow queue. Or maybe GOG has nothing to do with it, and the server people decide. Or maybe location plays a part. Or the size of the game. I'm obviously just speculating here, but not knowing how it works is frustrating.

Ok, believe what you want to believe then. I don't care.

I'm download a new purchase, as I'm typing this, and that download is averaging between 8 and 14MB(megaBYTEs) per second. But hey, it's not your ISP, is it...

I downloaded a few updates before making a purchase a few minutes ago and those were faster than the new game, about 18MBps. Maybe it is server dependent. I think it's more likely ISP related throttling.

But hey, it's not a Fastly CDN routing issue, is it.

This is completely and utterly false. Galaxy is a very solid client (though the third-party client integrations absolutely suck). If anything, GOG needs to dig deeper into improving it and the site's social features, as both are major parts of why people stick with Steam over competitors (particularly Epic).

As long as it remains optional, that's all that matters. I'm in a different head space than I used to be when I would hang out here a lot but I still firmly disagree with the Galaxy hate. It makes absolutely no sense. If you don't want to use it, cool, don't use it. That doesn't mean GOG needs to get rid of it.

As for my perspective on this issue, I do agree. I use Galaxy whenever I'm playing games but when it comes to downloading the offline installers for games, I'll have downloads fail, speeds will sometimes start high and then rapidly crawl later on, and so forth. It got to the point where I've basically stopped downloading the offline installers (which also means I've effectively stopped shopping here in general, though not permanently)... which sucks, because I like having those offline installers to fully own what I buy. It's just that, with slow speeds and regular failed downloads, I just don't feel the desire to waste more of my time -- which is considerably limited these days -- struggling to get the stupid things to download properly.

Agreed. While I rarely use Galaxy (mainly just to test it out), it is quite important for people who play Early Access games (due to constant updates), cloud saves, online multiplayer and maybe even achievements (or so I've heard some claim). I tend to play older GOG games that don't need these though. As long as Galaxy is indeed optional to play the games...

Also the little I've used Galaxy, it seemed quite ok to me. Not sure why I should hate it compared to e.g. the Steam or Epic client.

Does that happen both with Galaxy and a web browser? Or how do you download your offline installers?

If using a web browser, it might make sense to try to force GOG to use some other download server that where it likes to connect you normally, in case it helps. It does seem to help some and at least I've noticed how different GOG download servers act differently (e.g. one seems to limit total download speeds to 25 Mbytes/s (no matter how many files you download at the same time) while another limits it with 5 MBytes/s per file, multiplying if you download several files at the same time, etc.

Of course there may be issues at your ISP or e.g. your security suite as well (in case it starts blocking GOG for some reason), so it might help to try also on an alternative internet connection (different ISP) and a different computer, if possible. At least some Australians seem to have persistent problems with GOG downloads...

My speed is under 1mb/sec most of the time now, the problem just seems to be getting worse. I might have to install Galaxy and see if there's any improvement.

Yeah, tonight it got so bad I gave up downloading. Fluctuating between somewhere between dial-up and DSL speeds. I'll eventually trial Galaxy as well just for a test, but I'm not going to accept that as acceptable service by GOG even if Galaxy gives me full speed. In other words I'm not using Galaxy, GOG. Get your house in order.

It all started around the time of GOG's server crash, and I'm blaming their current choice of CDN which services their offline installers via browser.

GOG needs to send someone to Oceania to check what the heck is happening there.

I just tested downloading three files from GOG (The Legend of Heroes: Trails into Reverie), each downloading at around 12 MBytes/sec = 36 MBytes/sec combined speed. This was on Windows 10 using the Edge browser.

It would be nice to understand what is causing such variance.

Could it not be Fastly prioritising lower latency connections on some of its CDNs, and not utilising its local Oceania servers for GOG's files? We get bounced to North American servers, and I've found time of day has more often than not an impact as well which might indicate peak demand times up there. What we really need is a Fastly server down here servicing the downloads. Or a country somewhere closer ffs.

Speed wasn't an issue a couple of years ago. It certainly is now though.

Yes, I'd say Galaxy is the second-best of the official clients out there; Steam is objectively the better client but Galaxy is definitely second-best. Now, throwing third-party clients into the mix (such as Playnite on Windows, or Lutris/Heroic on Linux) would make it a bit more debatable, but as far as official ones go, Galaxy ain't half bad.

As for the issue, it tends to happen in both but mostly within a web browser. I've never tried downloading the offline installers via Galaxy, I might give it a try one of these days.

If you are using Galaxy already, the test is only a couple of clicks away. Then you know.

Wish i had your DL speed. I only get 3MB/sec. I would not complain if i had 12mb/sec let alone 36mb/sec.