If you try to launch a game and see error code 0x800B0016, it could be because GeForce NOW could not set User Datagram Protocol (UDP) socket buffer size.
This knowledge base article will:
Confirm whether UDP buffer size is causing the problem
Help you understand the importance of UDP buffer size
Increase the macOS X UDP buffer size
Provide a way to restore your system settings in the event that the recommended changes to fix this issue are not successful
Advise you about potential side effects caused by changing UDP buffer size
How do I confirm that the UDP buffer size is causing the error?
Open Terminal, which can be found in your Applications folder. You will be typing in commands in the Terminal window. If you are not comfortable with this, please reach out to NVIDIA Customer Care for further guidance.
First, check the current UDP buffer limit by typing the following command:
You will receive the following response:
“kern.ipc.maxsockbuf: xxxxxxx” where xxxxxxx is UDP buffer size, which is measured in bytes.
A UDP buffer size of less than 1048576 bytes indicates a problem.
What is the UDP buffer size? Why does it matter for GeForce NOW for Mac?
The GeForce NOW app uses UDP buffers to transfer audio and video from our cloud servers. By default, macOS X limits the maximum buffer size to 8MB (8388608 bytes). This value is enough for the GeForce NOW app to work. However, in some rare cases, other applications may modify this value to a much lower setting, which causes the GeForce NOW app to display an error and fail to configure the UDP sockets correctly.
Increase the OSX UDP buffer size
One way to fix the problem is to increase the maximum buffer size in macOS X. In most cases, this should be harmless to do. However, you should first investigate why the value was lower on your system. If you have other applications that rely on the current UDP buffer size setting, then the changes below may cause errors with those applications. Also, NVIDIA can not guarantee that these settings will persist. If there is another application on your Mac with admin privileges, it can override your new settings on reboot, or when an app update is applied.
To implement the UDP setting change, follow these steps:
Save your current setting using the following command in Terminal:
“sysctl kern.ipc.maxsockbuf > ~/maxsockbuf.bk.txt”
Note that the backup file ~/maxsockbuf.bk.txt will contain the current buffer size in bytes.
To update the value immediately, type the following commands:
“sudo sysctl -w kern.ipc.maxsockbuf=8388608”
If the command outputs “kern.ipc.maxsockbuf: X -> 8388608” then you've successfully changed the setting. Try launching the game again. The issue should be fixed, and you can stop here.
If the command outputs “kern.ipc.maxsockbuf=8388608: Result too large” please contact NVIDIA Customer Care, and we will guide you with additional steps to resolve this issue.
Restoring UDP buffer size
If you encounter problems with the UDP buffer size with other applications, you may need to restore your original settings. To restore the settings you had, use the buffer size value in the backup file ~/maxsockbuf.bk.txt . For example, if the buffer size in maxsokbuf.bk.txt is 512000, you would run this command:
sudo sysctl -w kern.ipc.maxsockbuf=512000
Please contact NVIDIA Customer Care if you experience any other side effects after changing UDP buffer size.