When RENDERING or EXPORTING, read/write speed is inconsequential. It makes a very big difference when previewing. Until Adobe gets its s**t together and actually finishes its long-promised render speed improvements, it will remain that way.
The rendering speed has little to do with the speed or connection to the cache drive. Rendering speed and rendering a preview speed is 95% what you are doing in the comp. For many of my comps my rendering speed can easily be 2 or 3 minutes a frame. Some comps, however are rendering at 3 or 4 frames per second. It just depends on what I am doing.
SSD's will improve IO performance for sure, and they can speed other things up dramatically but don't expect your RAM previews or Renders to dramatically change. As long as you don't have other software computing for bandwidth to and from your drives rendering speed is not going to change much.
If you have the cash and can afford good reliable SSD's you will save some time over the next few months. Just how much time depends on how much rendering you do and how much real time previews you can live with. I can tell you that I seldom do a ram preview of anything longer than a second or two for anything other than what I call a "pencil test." By Pencil test, I mean preview motion only, effects off and comp panel set to 50% or even less. I check full frame full resolution "hero" frames with everything turned on to see if I have the results I want, then if the "pencil test" was Ok and the "hero frames" look Ok I just render because I can't make any money waiting for ram previews. After you have been at this for a while anybody can get a good idea what the final render will look like without relying on a full frame, full resolution, all the effects added ram preview. It's a more efficient way to work.
Thanks you for your thoughts.
I've tweaked just about everything I can tweak inside AE at this point, and on many of these animations I'm previewing at Half/Quarter resolutions, disabled FX, etc... just to get something in the cache at a reasonable time. It's very hard to NOT do at least 5-:10 of previews with the kind of work we do. Very nuanced, articulated animations that I need to be able to play back at full speed. Anything less than that would be like composing a piece of music one measure at a time.
It sounds like, so far, my drives aren't factoring into it, as much as AE's ability to simply process each frame.
This sounds extremely frustrating. Your issue might be more related to workflow than hardware, in my opinion.
When working with high-resolution stills, I've found that performance is degraded the larger you go. You can often have an easier experience and smoother workflow with images that aren't quite as large. I use Lightroom to batch convert images for use in After Effects. Can you try that? Come on back to the thread for more support.