1. With 16gb, will an AMD 8 core give significant benefits over an AMD 6 core, please?
No. Simply do the math: 16GB/8=2GB per core, 16GB/6=~2.65 GB per core, assuming you were to use all of them just for AE with MP rendering. A marginal difference at best and then of course the usual "if you use feature X, it will nmot use MP rendering..." disclaimers apply.
2. Is there any benefit in spending a little more on a GT640 or will the 610 suffice, please?
Zero. CS5 did not use anything beyond basic OpenGL. Any such decision would be much more dependent on third-party plug-ins that may use GPU-acceleration.
Thanks for the info.
However, I did a different math - 8 cores at 4.0 ghz each is better than 6 cores at 3.9 ghz.
Are you saying that CPU power doesn't matter? That RAM is the only thing to be concerned with?
If so, am I better getting 4 cores so they have 4gb RAM each, or even 2 cores with 8gb?
Sorry this is such a basic question, but I really have no idea about this subject.
Mylenium replied to the option you gave him - you didn't mention clock speed.
CPU is the most important factor to After Effects (so long as the CPUs have enough RAM). So, of course 8 x 4.0Ghz cores will render faster than 6 x 3.9 Ghz cores.
16Gb of RAM in an 8 core machine is not ideal, but will generally perform well. If you're working on a memory intensive project you can always reduce the number of cores utilised temporarily.
If this purchase is meant to last you a few years, I'd go with the 8 core machine, but make sure your RAM is configured appropriately (with some free slots) so you can add 8 or 16Gb extra when your budget allows.
Thanks for elaborating on the CPU issue.
If renders fail due to memory issues, are you saying I may be able to simply reduce the number of cores to, for example, 4, so they each have 4gb RAM instead of only 2, to get around the issue?
I hope I've read that right because it's really interesting and something I'd never thought of.