Mercury Engine in After Effects CS5.5? Or, why is After Effects so much slower the Premiere Pro?

Question

Take this quote :
"by Todd Kopriva on Apr 25, 2010 at 8:08:14 am
'Mercury' is a marketing name for these performance improvements in Premiere Pro: - multiprocessing
- multithreading
- 64-bit application
- use of CUDA to to some processing on supported hardware 
The first three of these are in After Effects CS5. (The first two have been in After Effects for much longer.)"
However, if I drop my Canon 5D Mark II footage (h264) into Premiere Pro it plays back SO MUCH better then the exact same footage in After Effects. Why is that? I DO NOT have an NVideo card and I have NOT applied any effects or scaling to the clip, just raw footage dropped into each program.
I do notice that After Effects has to render to play back (green bar being generated above footage). But it does slow very slowly, like 9fps. Premier Pro seems to cruise right along at near realtime. This is 24fps 1080p footage. One other point of interest, I have encoded the clip into Cineform codec as well. On Premier Pro I can tell a difference, the cineform scrubs a lot smoother then the original H264 clip. But, again, in After effects both the h264 and Cineform clips are very slow to render and scrub.
Any improvements along these lines for CS5.5?
Am I just missing something obvious?
Thanks for any info,
--greg.

Answer 1

Gregory Seattle wrote:
I think the problem is that hitting the space bar and hitting '0' (ram preview) both draw that green bar, and both seem to use it if it is already there. I guess the real difference is how that green bar gets generated. It does seem to get generated faster when I ram preview as opposed to hitting the space bar. Using both cores I have I guess (early 2009 24" iMac).
When you hit the space bar, AE TRIES to play back as it renders each frame.  Imagine what happens if it's a comp with 120 3D layers that all accept lights and cast shadows.  That's why you don't use the space bar.
In a RAM Preview, AE fills up the memory available to it with rendered frames, then plays them back from RAM.  Depending on processor speed, dimensions of comp & frame rate, this may or may not be real time, but there are ways to get real time.  With the space bar, you don't stand a chance at real time.
Gregory Seattle wrote:
From what I hear new iMacs are due out soon with the new Thunderbolt (!) and Sandy Bridge processors/chipsets. Should be a LOT faster then what I have now.
For AE work I'd say maybe yes, maybe no.  To make AE REALLY speedy, you need a lot of processor cores and a boatload of RAM.  iMacs aren't known for either of those things.