🐞 Battle.net download throttling bug

I was told to move this to the bug report forum.


I tried to see if I had the same issue and I don’t :confused: you doing something specific?


  1. Uninstall Hearthstone if you have it installed. (It is the smallest game to download)
  2. Set your Network Bandwidth/ latest update limit to 1000 kb (1mb/s).
  3. Start downloading hearthstone.
  4. Note the CPU usage of Agent.exe.
  • On my machine it reports around 12%. I have an 8 core cpu (4 hyperthreaded), so 100% / 8 = 12%. It is pegging a single core.
  1. while hearthstone is slowly downloading at 1MB/s change the limit back to 0 kb (unlimited).
  2. Note the CPU usage of Agent.exe
  • On my machine it drops to about 1%, and the cpu fan becomes quiet (which is why I noticed the problem in the first place).

I would be very surprised if someone else doesn’t experience the same thing. I have reproduced this behavior on three different machines.

Same here. I am updating my COD MW.
In the night time, cpu fans are making white noises because of the update agent that takes about 30% CPU usage ( i5 - 4690 )…
The CPU usage goes down to less than 6% as soon as I set download speed limit to 0.

Yeah, this is really irritating. I show a fairly slow connection so I have to throttle downloads for the sake of others, so I’m running 30%+ usage for days on end. Torrent programs don’t do this when throttled, wish Blizzard would address the fact the app does.

Im having the same problem. but I did not know that it was the throttling. I thought battle.net just did this while downloading a game. I have not installed Battle.net in years. As soon as I set the values back to zero for unlimited, no problem.

So I sat my MSI GL65-9SD on full fan speed all the way through 30GB of World of Warcraft at 3000 kb as we have a few people on a single connection…

Back to leaving it on over night when the full 7500 kb speed is avaliable if I want to play a new game.

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The bug is still there !

Now that I have fiber optic at 400 Mb/s, I’d like to set a speed limit to get more bandwidth available for other tasks, but every time I set the lesser value, CPU usage increases by 20%.

Blizzard team say that only a “few” people have reported this, and may think that this is a minor or “niche” - I quote lmao - bug that could eventually get fixed by sending them Windows log files (lmfao).

This bug is GLOBAL and may affect millions of players right now.
Also, most people don’t want to lose their time posting on the forums and are just hoping for those kind of bugs to get fixed fairly fast ! (though amongst the few people who are using bandwidth limiting, only a very few are taking the time to report the bug).

To the devs/blizzard guys :
It is not a user bug since it is included in the Battle.net program… it just can’t be unseen, and please stop saying “it’s how the program works, compression stuff etc”, having 5% cpu usage at full speed and 27% when limiting the bandwidth is in no way related to how the program works. Stop acting like ignorants…

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This bug also exists for me. The throttling isn’t an excuse to use up almost 100% of my CPU. The fact that my machine is literally screaming for help is a message on its own that this is a recognizable bug.

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Also have this issue. Ridiculous that it’s existed for so long.

I have this issue as well. Its the download limiter for sure. I can set any value, even 10kb and it causes a 20-30% cpu increase. Set to unlimited, and it relaxes again. This is a bigger problem being on ryzen with precision boost. It causes my cpu to run at 1.38volts and max boost clocks without dropping and 45C on the cpu. This also translates to a 30 watt increase to cpu power draw. With no limiter, my voltage can fluctuate down to idle voltages and my cpu temperature hovers around 30c and the clocks also fluctuate back down to idle clocks. This absolutely needs to be fixed. Being on a slow 5mb dsl internet (fastest available) it really is a feature I NEED to use. Please address this Blizzard.

UPDATE: I was able to install NetLimiter4 to set my desired download/upload speeds. Leave blizzard set to unlimited. Things are normal now. Clocks/Voltages fluctuate to idle and heat stays at a good idle 30c. Would be nice to avoid yet another 3rd party software to resolve such an issue. Temporary fix anyhow.



Here we are, more than a year after I reported the issue originally (in the other forum). We’ve recently seen a massive overhaul to the launcher app, and the issue still exists. It’s pretty clear at this point that they just don’t care and this issue will never be fixed. Annoying.

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i have same problem gpu fan speed goes to 30+
thats not what i want i like my fan speed at 70 so the gpu always cool

any updates on this bug? funny thing is I thought my old pc was faulty for 4 years and couldnt confirm it until the new laptop woke me up with really loud fan noise, I left it downloading warzone overnight, only to find it suffering with high cpu usage and redundant heat and energy just because I had the download limit enabled. I turn the download limit off and instantly the cpu usage went down from 30% to 1%??? really? at this point I dont really care if blizzard fixes any of their stuff, Im just too curious as a fellow game developer to know how essentially can an option to reduce network bandwidth load by commonly pausing download handler tasks put a 30% load on the cpu?

This is still not fixed. At 30MB/sec i have 1% cpu usage. If i used Battle.net built in download limiter and set it at 25MB/sec it jumps to 20% cpu usage. It’s been 3 years Blizzard

I fixed it, disabled the automatic update!