Download speed limiting causes High CPU usage

As the title says, applying any download limit causes around 30% increase in CPU usage on my machine. That’s more than 1 core on my 4-core i5 7600k.

Refer to this URL for an example because i can’t give links imgur(.)com/a/gDzpUhY

Not bad, considering games will use all of your CPU at 100% if it can. But this is just a launcher. Not even that, “Blizzard Update Agent” is the updater for games installed on your device.

Yes, I’m aware that its not just simply downloading, it’s also decompressing and installing, similar to Steam downloads. But why the sudden increase in usage? 30 times more compared to without a limit?

Is it taking advantage of the limit in network usage to start decompressing the files? That would be smart, and I’m hoping thats what it is. But I’ve already seen one customer support grunt disregard this as normal behavior and, out of their hands (in the category of Desktop App Tech Support):


So, what now?


hey, I am having the same issue. If I limit the download speed to anything else bellow unlimited, Blizzard Update Agent will use almost 30% of my CPU. That cause my PC to run slow or even lag when doing other task. On the other hand, if I set the download speed to unlimited, it won’t use my CPU as much, only 2%!!! The big issue is that it will use all my internet instead of my CPU and I won’t be able to browse the internet properly. Either way it causes lag. Blizzard is getting really annoying, I can’t go for a 30GO update on full speed and I need my 100%CPU FREE of garbage.

please fix this Blizzard.

Same here, a bit ridiculous, but considering how badly optimised the launcher and warzone is for PC im not surprised.

Im going to try lowering the cpu priority but doubt it,ll work.

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Best solution i could find to stop it turning your pc into a heater is as follows… :man_facepalming:

Go to Control Panel.
Hardware and sound.
Power options.
Edit plan settings.
Change advanced power settings.
Processor power management.
Maximum processor state and lower it to 80% or whatever you want.

I have this issue too, my fan speeds all ramped up whenever I throttle download speeds. Took me a while to figure out what was causing it. Blizzard update agent ramps my i7 7700K up to 15%, and the power usage sits at Very High. When I disable to download limit, the update agent drops to 1%. Wish I’d known this before I tried to download Black Ops while also watching a movie on Netflix!

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

Also wanted to chime in here on this issue because it was happening to me as well.

The only way I’d been able to keep the CPU under control was by minimizing the window (importantly, NOT closing it causing it to minimize to tray).

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