Well, clip formats need to store there frames consecutively, don't day? You can't expect MP rendering to defeat that. If you want to max out performance, use image sequences, otehrwise you'll have to live with this limitation of each instance having to wait for the otehrs to have written the frames in proper order.
Right, so does that mean the Ram Preview is writing frames non-consecutively and that's why it's so much faster ? I still don't understand why the CPU useage would be so different.
I wish I could use image sequences but these are 1-2 hour videos that are being rendered.
One to two hour movies produced entirely in AE may not be the best use of the software. It's hard to tell with knowing more.
Image sequences can be as long as you like. Most of the renders that visual effects houses produce when making a feature film are image sequences. They are just more efficient. A jpeg or png QuickTime is just an image sequence in a .mov wrapper. If I were attempting to render a two hour project in AE I don't think I would even consider rendering to a format that may break if the render fails at some point. With an image sequence you can pick it up to fix just one frame if you need to.
As Mylenium said there are a lot of limitations with system resources that come into play when you are rendering to a video codec. Some do not support multi processing at all, some have limited support. There's no reason yet to expect that rendering to a video codec will be as efficient as rendering to an image sequence.
Right, so does that mean the Ram Preview is writing frames non-consecutively and that's why it's so much faster ?
Correct. It behaves like it would with image sequences.
Jeff, sorry to hijack the thread, but I have a question...
If the JPEG Quicktime file is just a series of JPEG images in a quicktime wrapper, why choose one over the other?
Are they technically exactly the same?
because an image sequence will render faster. The QT or AVI wrapper forces the rendering to be sequential.