Starting version 2.1.0 of Elgato Game Capture HD software for Windows, there will be a warning message displayed if problems are detected during streaming.
Namely, the software will inform you if there are issues with the upstream bandwidth or video rendering.
Warning Message - Low Upstream Bandwidth
If you are experiencing Low Upstream Bandwidth, a message will appear with either an Orange or Red dot next to it.
An Orange dot indicates a general warning:
A Red dot indicates a critical warning, meaning that your bandwidth is particularly constrained:

This warning appears if your connection to the streaming server is too slow to upload video at your selected bitrate (in Mbps). Potential solutions are to check your internet connection, select a different server, or reduce the streaming bitrate.
Troubleshooting Low Upstream Bandwidth - Choose Another Server
Choose another server for streaming to Twitch. You should try one that's close to your physical location, and that has low latency.
Troubleshooting Low Upstream Bandwidth - Reduce Streaming Bitrate
Reduce the bit rate for streaming, via the Live Streaming section of the Elgato Game Capture HD software.
Troubleshooting Low Upstream Bandwidth - Stop Uploads/Downloads
Stop any downloads or uploads that are using the same internet connection at the same time, so that Elgato Game Capture HD streaming can be the focus of your network activity.
Troubleshooting Low Upstream Bandwidth - Check Network Bandwidth
Make sure that your WLAN / LAN connection provides sufficient bandwidth.
Troubleshooting Low Upstream Bandwidth - Check Upload Bandwidth
Make sure that the upload bandwidth of your internet connection is sufficient.
You can check it here:
http://www.speedtest.net
You may need to contact your ISP (Internet Service Provider) if the upload bandwidth is much lower than expected.
Warning Message - Cannot Render
If you are experiencing problems with rendering video, a message will appear with either an Orange or Red dot next to it.
An Orange dot indicates a general warning:

A Red dot indicates a critical warning, meaning that it is particularly hard to render video at the chosen resolution:
If you want to find out more about the warning, you can click on it:

This warning appears if your computer cannot render the currently selected frame rate smoothly. Potential solutions are to close other applications, or to choose a smaller output format.
Troubleshooting Bad Performance - Choose Hardware Accelerated Decoder
Choose a video decoder with hardware acceleration. You can find that option in the Advanced section of the Preferences.
Troubleshooting Bad Performance - Choose Hardware Accelerated Encoder
Choose a Stream Command Encoder with hardware acceleration. You can find that option in the Advanced section of the Preferences.
Troubleshooting Bad Performance - Lower Quality Setting For Video Encoder
Lower the "Best Performance / Highest Quality" setting for the Stream Command Encoder.
You can find that option in the Advanced section of the Preferences. Move the slider to the left, towards Best Performance.

Troubleshooting Bad Performance - Reduce Resolution For Live Streaming
Reduce the resolution for streaming, via the Live Streaming section of the Elgato Game Capture HD software.
Troubleshooting Bad Performance - Lower Capture Resolution Or Frame Rate
Lower the resolution and/or frame rate of your Elgato Game Capture HD or Elgato Game Capture HD60, by visiting the Capture section of the Settings window.
Troubleshooting Bad Performance - Close Other Applications
Close other applications that have high processor or graphics processor utilization.
Namely, the software will inform you if there are issues with the upstream bandwidth or video rendering.
Warning Message - Low Upstream Bandwidth
If you are experiencing Low Upstream Bandwidth, a message will appear with either an Orange or Red dot next to it.
An Orange dot indicates a general warning:
A Red dot indicates a critical warning, meaning that your bandwidth is particularly constrained:
If you want to find out more about the warning, you can click on it:
This warning appears if your connection to the streaming server is too slow to upload video at your selected bitrate (in Mbps). Potential solutions are to check your internet connection, select a different server, or reduce the streaming bitrate.
Troubleshooting Low Upstream Bandwidth - Choose Another Server
Troubleshooting Low Upstream Bandwidth - Reduce Streaming Bitrate
Reduce the bit rate for streaming, via the Live Streaming section of the Elgato Game Capture HD software.
Troubleshooting Low Upstream Bandwidth - Stop Uploads/Downloads
Stop any downloads or uploads that are using the same internet connection at the same time, so that Elgato Game Capture HD streaming can be the focus of your network activity.
Troubleshooting Low Upstream Bandwidth - Check Network Bandwidth
Make sure that your WLAN / LAN connection provides sufficient bandwidth.
Troubleshooting Low Upstream Bandwidth - Check Upload Bandwidth
Make sure that the upload bandwidth of your internet connection is sufficient.
You can check it here:
http://www.speedtest.net
You may need to contact your ISP (Internet Service Provider) if the upload bandwidth is much lower than expected.
Warning Message - Cannot Render
If you are experiencing problems with rendering video, a message will appear with either an Orange or Red dot next to it.
An Orange dot indicates a general warning:
A Red dot indicates a critical warning, meaning that it is particularly hard to render video at the chosen resolution:
If you want to find out more about the warning, you can click on it:
Troubleshooting Bad Performance - Choose Hardware Accelerated Decoder
Choose a video decoder with hardware acceleration. You can find that option in the Advanced section of the Preferences.
Troubleshooting Bad Performance - Choose Hardware Accelerated Encoder
Choose a Stream Command Encoder with hardware acceleration. You can find that option in the Advanced section of the Preferences.
Troubleshooting Bad Performance - Lower Quality Setting For Video Encoder
Lower the "Best Performance / Highest Quality" setting for the Stream Command Encoder.
You can find that option in the Advanced section of the Preferences. Move the slider to the left, towards Best Performance.
Troubleshooting Bad Performance - Reduce Resolution For Live Streaming
Reduce the resolution for streaming, via the Live Streaming section of the Elgato Game Capture HD software.
Troubleshooting Bad Performance - Lower Capture Resolution Or Frame Rate
Lower the resolution and/or frame rate of your Elgato Game Capture HD or Elgato Game Capture HD60, by visiting the Capture section of the Settings window.
Troubleshooting Bad Performance - Close Other Applications
Close other applications that have high processor or graphics processor utilization.