ENVE allows you to manage the performance of the application using more CPU or GPU or a mix of both. At the bottom right of the application window the performance of your GPU, CPU, hard disk and RAM is displayed.

You can try modifying the Acceleration preference bar to check which is the best setting for your computer.

1.1 Resource optimization for slow computers

If at any time the RAM bar is full that means that you may not be able to preview the entire animation. To fix this, close applications that are currently consuming RAM, such as the web browser.

Resolution

Another way to reduce the power consumption of the computer is to lower the quality resolution on the screen. 

This does not affect the final rendering, only the way the preview is viewed.

Filtering

Lowering the Filtering level shows the edges of objects less smoothed but also helps to improve performance on slower computers.