You can adjust your streaming bandwidth from the Steam Link main menu, or live in Big Picture Mode and in-game.

When adjusting your bandwidth, you should start at the lowest setting and start slowly increasing the bandwidth until you see problems, and then back down to the last setting that worked. If you want to reset to the default behavior, select the "Automatic" setting.

Steam Link main menu:

1. Select Settings
2. Select Streaming
3. Press the (Y) button to enter Advanced Client Options
4. Adjust the Bandwidth Limit option

Big Picture Mode:

1. Select the settings icon next to the power icon in the upper right
2. Select In-Home Streaming
3. Select Advanced Client Options
4. Adjust the Limit bandwidth option