Yeah, 4GB of RAM is your problem, not the laptop. My Mac Pro desktop at work is a few years old and only had 4GB of RAM when we first installed CS5 and it was horrible. Upgraded to 8GB and it works fine now.
[Benjamin Pastrana]"I have a Macbook Pro 2.53 Ghz Intel Core 2 Duo with 4GB RAM 1067 Mhz DDR3 but is imposible to render with AECS5!"
AE renders faster through multiprocessing, where it runs a couple instances of the renderer simultaneously. Each instance works on its own frame, on its own core (physical or virtual), and in its own space in RAM.
If you have multiprocessing turned on with only 4GB of RAM, you should turn it off! When your system is that memory-constrained, multiprocessing will actually hurt your render performance.
Does your new computer really have to be a laptop? You'd get way better performance for the same price on a desktop system with multiple cores and lots of RAM. You could always keep your current laptop for when you really require portability.
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