Why low upload in Windows 7/10/?

Question

Computer networks

Good!
There is a computer, on I7, with two setevukha. One for the Internet, the other for network devices. In whatever network card I turn on the Internet, the upload / download is about 100 Mbps, which is verified.
If you enable a bridge connection, then the upload goes up to 0.2 Mbps, almost from 100! The download speed is reduced by 20 percent.
It was a long time ago, I tried to enter for a long time, which limits the speed, searched for a long time, consulted ... As a result, I redid the system so that the bridge was not needed and I forgot this terrible dream. System on Win 7 x64 ultimate.
Now, a slightly different system on Win 10. I'm forwarding openVPN and making a bridge to connect to the Internet under the desired ip. Everything is gorgeous, let me think I’ll look at the speed on speedtest, and lo and behold, the same situation, although in this case the download speed has not decreased much. I send a file through the tunnel: 22 Kb / sec. I turn off openVPN, I go via RDP, I run the test - the expected 100 Mbps, in both directions.
I call the provider, you never know, "heel in the chest", they don't block anything.
As a result, interest began to play with renewed vigor, what the hell is the matter?

Answer 1

Anatoly did not find performance data for such bridge connections, however, it is indicated that CPU resources are used - this is probably the reason for the low performance of the bridge. Even despite the productive CPU - probably this code (responsible for creating bridges) has not been updated for a long time and is not optimal - does not provide acceptable speed.
I recommend abandoning such software bridges and using hardware routers instead.