In the Cisco IOS on a Catalyst switch (not on a router), there’s an Interface Mode command called shape round-robin queue bandwidth. More specifically, the command is srr-queue bandwidth.
This command has been around since IOS 12.2(25). For these examples, I’m using a Cisco Catalyst 2960 switch.
Entering the command appended with a question mark will display the command options. Here’s an example: