To improve display performance, you can select the display quality of transparency.

On the Edit menu, click Preferences, and then on the Display tab, drag Transparency/Shadow optimize slider where you want.

Drag to Quality to get the best display quality.

Drag to Speed to get the best display performance.

Drag in the middle to have medium quality and acceptable display speed.

There are also additional two steps between Quality and medium, and between medium and Speed.