'Limit download bandwidth' not working as expected

My connection maxes out at around 4.2 MB/s, so I tend to set programs such as Steam, Origin etc. to 4.1 MB/s, so it doesn’t slow down everything on the network as games/updates download.

Within the Battle.net desktop app, I’ve gone to Settings then Downloads and set both boxes under ‘Limit download bandwidth’ to 4,100 KB/s.

However, according to the program (bottom left of the home screen), this is limiting my downloads to around 3.5 MB/s.

Setting them both to 5,700 KB/s seems to level the downloads at around 3.9-4.1 MB/s.

Can anyone assist?

First of all, I’d look into some other ISP honestly, because those rates are terribly low in this day and age, but I’m aware that’s not the question, just something to consider.

Secondly, I took a look at it and the problem’s not something on your end, but in the Battle.net client itself. I tested with a 10.000KB/s limited download and this resulted in about 8.8MB/s. Math isn’t my strongsuit, but it feels like way too much of a difference to be accounted to the common 1024 MiB vs. 1000MB misconception.

Also worth noting is that the difference you’re experiencing is about the same as mine, while I configured double the limit, so it’s unlikely to be a percentage.

Therefore, my guess is that it’s probably programmed in such a way that the entire Battle.net client’s data usage is limited, but that it also uses part of the bandwidth to communicate other data while downloading, thus resulting in a seemingly odd download-speed, while technically doing what you configured.