I am not sure if it is supposed to be like this but, my CPU utilization is around 75% when I was downloading Witcher 3.

What's your connection speed / how fast were you downloading the game?

Since I switched my internet to Gigabit I learned that high download speeds in general are causing higher CPU load.
This might not necessarily has something to do with Galaxy itself.

The game was being downloaded at 45 MB/s, but on steam my CPU usages stay around 20% though.

Same issue here. CPU load is around 30% when downloading with 50 - 80 Mbit/s

Also noticed that when I throttle the download to 25 Mbit/s in the Galaxy settings, it will only download with 8 Mbit/s. With 50 Mbit/s the actual download rate is 16 Mbit/s.

Steam utiilizes about 5% of the CPU when downloading with 75 MBit/s

I'm glad I'm not the only one. I wanted to chek out discounts, but the computer became unusable because GOG started donwnloading update for a game. That can't be normal, Ive never witnessed such behaviour.

Edit: it seems this only happens when updating a game. I uninstalled it and tried downloading it again. CPU usage was still too high I think, it went up to 60%, but at least it didn't make computer slow down to a crawl, so I could continue using it while downloading.

Edit2: Tried accesssing store while downloading; same result. Computer slows to a crawl. Minimizing galaxy to tray solves the problem...

I'm having the same issue. Downloading at 36 MB/s and my CPU usage is at 100%. Brought my computer to a crawl until I changed the process priority to below normal.

fake news

I know how it works on Steam and i think it is not different on Galaxy.


If you download a game its compressed and the higher the download rate the more data needs to be extracted. That is causing your high CPU usage and makes the CPU to a bottleneck at high download rates.

True, but it have also happened when just downloading the installer. Nothing is extracted, it's simply just downloading the files.
The client also used to be hogging a few percent of the cpu when doing nothing.

Not particularly versed in the topic downloading..... But I guess downloading in a high speed is more resource expensive than what one may think. Went from 100/100 to 250/250 earlier this year and I'm seeing higher cpu usage during downloads than what I used to see.

That may be the case, but when the GOG galaxy stresses the CPU just as bad as running Prime95 that's a badly coded download manager.
I just downloaded Metro: Last Light Redux and was very surprised when my fans ramped up like crazy.
Sure I have a gigabit connection, but that does NOT happen when downloading from steam or any other game launcher for that matter.

I'm downloading the first Dishonored right now and my CPU is staying at ~ 41%. GOG Galaxy itself is using 17% from those 41% at the moment. My download speed is at 11 MB/s (102,6 Mbit/s). Everything seems normal on my end.

Crazy how only GoG Galaxy does this. Like AlenCT said minimizing to system tray helped keep the temp down and keep fans from ramping up while downloading updates.

Yeah uh no.

Temps in the left when playing Apex legends in ultra settings, temps in the right when downloading Cyberpunk