I ran this checker for the upcoming Invision Powerboard 3.0
IP.Board 3.0 Requirements Checker
Checking for mysqli support...FAIL
The mysqli extension is preferred over the original mysql extension. If you are utilizing another database driver (such as MSSQL) you can ignore this message. This is not a requirement, but if possible we recommend you to install the mysqli extension for better performance.
I thought the php is already compiled with support for mysqli with the following parameters.