You may have an issue, but it is unlikely the motherboard itself. The gaming 5 is a very good board. I can't recommend buying a new Z97 board because the prices have went way up. If you really want one though, an Asus Z97-A used to be the go-to Asus board. Not sure they are sold anymore though. Then you have the issue of buying a new copy of Windows.
Are you having issues with any other programs or games?
If we had more information we might be able to help you. I prefer 3dmark (firestrike or timespy) as it gives a lot of information at a glance. You can also check to make sure your RAM is running in dual-channel mode and your graphics card has sufficient airflow. What does your GPU usage graphs look like when playing GTA 4 (can use...