I'm experiencing performance issues when using an eGPU, how can I resolve this?

When using an eGPU, you may experience performance issues for the following reasons:

Your eGPU is plugged into the wrong port on your computer
You may experience reduced performance if your eGPU is not plugged into the correct port on your Mac. Please consult the Notes section at the bottom of Apple's eGPU guidelines.

Performance is limited by your processor (CPU)
Game performance is determined by a combination of your computer's graphics processor (GPU) capabilities and the power of its central processor (CPU). In particular, many graphical effects use the computer's GPU and CPU in unison; an eGPU has the potential to support better graphics, but there may still be limitations due to your computer's CPU.

Please note: DiRT 4’s default settings have been fine-tuned give you a good overall gameplay experience. If the default settings are altered, performance may be adversely affected across the game.