Current (and since a certain patch), the download speed limit input interpretation is bugged. It's relatively easy to work around though. To set a certain download value, enter that value multiplied by 3.

So, if you want 1MB/s, set it to 3MB/s. Want it at 900KB/s so that your other devices on the wifi doesn't become brain dead as they are unable to connect to anything? Set it to 2700KB/s.

There is an hard-cap limit set by the GoG server so you might not be able to reach an high MB/s value you set even if you have the bandwidth for it and there's also the issues that came with the release of Cyberpunk which affects GoG servers' capacity since the number of people downloading from it must have raised dramatically in the last few days.

Still, multiplying the target value by 3 seems to works close enough.

I confirm the bug with Mb/s. Yes I multiply by 3 to choose a correct speed.

It would be very easy to correct it by GOG team...

Download speeds are bad because Galaxy is garbage

It's not your router, your firewall, etc. Do not use Galaxy to download games. Download the offline installers (through a web browser, NOT Galaxy) and install them. They will then appear in Galaxy. My offline installer downloads are 14.0MB/sec. Through Galaxy, they are 0.1MB/sec today.

This is crappy coding of Galaxy, nothing else.

Check if your Game Installation Path (right above bandwidth option) is where the game you're installing is going to.
Sometimes, when you install a game, you could be installing it to a different location (like when you have no more disk space). This is something unavailable to Steam, Origin, and EPIC and frankly, it's my most wanted feature to date.

My guess is that although this feature is super nice, it does mess with the bandwidth option by making any game being installed to a different path not reflect your bandwidth option (I've checked by installing a game to my second ssd and set bandwidth to 700Kb and got 2.2Mb/s).

Still though, this feature alone makes GOG the best interface that I've used so far, hats off to the devs.

This option not working properly. When I set 2Mbps I see in my NetMeter speed between 1kbps-2Mbps. But speed quickly go up and down. When I set off speed is continuously about max speed of my intenret connection. Setting in app is not to use.

Same here for me. Setting a limit throttles it way below specified.

edit: Also, it would be nice if it told me when the download fails instead of me having to check on it to know if I need to restart and wondering how long it had been idle.

Now I have this problem too. If bandwidth limit is set (in my case to 2 MB/sec) then I only get in between 0.6 - 0.7 MB/sec download speed.

Same here. If the limit is set to 3 MB/s or 3000KB/s, then the real speed comes out as 1.0 MB/s

I'm also facing this issue, where the bandwidth limit is 1/3 of what you set it. When I set the limit to 2 MB/s, download was at 0.6 MB/s. After reading the posts here, when I changed the limit to 6 MB/s, download is now going at 2 MB/s

came here to see if anyone else was experiencing this. i guess there's no fix for it and i'll just add this is still happening to me

Can't believe this is still happening, just had this happen this morning as well...
Unlimited: 18 MB/s
Set to 10 MB/s - I get 3.2 MB/s
Set to 15 MB/s - I get 4.8/4.9 MB/s
Set to 30 MB/s - I get 9.7-9.9 MB/s

Oh dear people, surely this silly little miscalculation in the D/L limiter could be corrected by now!? ...