I've got 100GB assigned to the Picture Viewer. My machine has 128GB.
It plays back similar to how After Effects does sometimes when it just won't play back full frame rate. Like, when After Effects is playing back a RAM preview and it will show in the info panel it's playing back at like 11 FPS out of 24.
In Cinema, it's definitely not playing back at the full 24FPS.
Yeah it's been a problem for years. The best solution I found was to do the following in After Effects:
Pre-compose the text and Luma Matte layers.
Then, to this new comp layer, add Effect/Matte/Simple Choker with a value of 1.0 to trim the extra pixel created by the Luma Matte.
I would imagine if you made the torus object an attractor then the particles would go and stick to it rather than pass thru it, Im guessing the collector may be a better place for it, tho i may not be seeing the whole picture.
There are generic shapes to use in the fall off tab I think.
Also check out the TP presets in the content browser