Creating compositions that are beyond 1080p may begin to cause problems if the GPU runs out of memory. One possible solution to lower memory requirements is to set the Element render settings before you start working. To do this you could do the following:
1. Turn on the Caps Lock to avoid rendering
2. Add Element 3D to a layer
3. Turn Multi-Sampling down to 2-4 which will lower the memory requirements
4. To improve Anti-Aliasing (But slow render) turn on Super-Sampling.
Changing the composition resolution for an already setup project can take a bit of work and can be a bit tricky. For example if you change your composition resolution from 720p to 1080p, and then just scale your solid that Element is on to fill the frame, it will look pixelated and blurry. This is because this is scaling the pixels of the layer and stretching the quality. Even if you select the Scale to Frame option, and then look at the layer scale it will be above 100%. It is not recommended to scale Element layer due to this. It is recommended to create a brand new layer the size of the comp and copy and paste the Element effect from the old layer to the new. Because the pixel scale is changed, your camera/position animation may not be in tact and may need some adjusting back into place.