I've just started using AE for some simple 3D work (falling triangles that rotate as they drop on a 1080x1080 comp), and I'm having trouble previewing the work in the timeline. I've had a couple of messages about low RAM, and I'm regularly emptying the disk cache. Attached is an image of my machines specs.
Really, I want to know if there are any setting I can play with to speed things up (having to export 3 second clips just to view my work is getting tedious), or if I just need more RAM.
I beleive the mimimum recommended RAM for AE is currently 16GB.
A couple of things you might try:
In preferences, After Effects > Preferences > Memory you can reduce the RAM reserved for otehr applications to free up more RAM for AE. The loweest it will let you set it is 1.5 GB when you have 8GB though.
At the bottom of the comp window, you can reduce the Resolution/Downsample of the comp you are trying to preview. Maybe set it to half or quarter, this will reduce the quality of the display but also reduce the RAM load.
As thepixelsmith mentioned, the minimum memory requirement for After Effects is 16GB. Both of their suggestions should help. However, allocating too much memory to After Effects might cause a bottleneck for other processes on your system, and you may experience a slow-down overall.