Throw out the term bottleneck from your vocabulary. The word has been misused to the point of meaninglessness.
For gaming, there may be some games where the CPU is what's holding it back. For other games, it may be the GPU that is holding it back.
Or, it could be the amount of RAM in your system that is at issue. Insufficient RAM can kill performance in some games.
Most important:
- What is your monitor's resolution?
- What is your monitor's refresh rate?
- Does your monitor have FreeSync, GSync, or neither?
- What specific games are you playing?