iMac 21.5" Specs - can you help me?

[oinky]

I'm looking to get a 21.5" iMac mainly for video editing, Photoshopping and After Effecting (and Sim 3ing) because I think I am slowly killing my little 13.3" 2.26 GHz 2GB RAM MBP. And also because I am so sick of chucking everything on an external hard drive because it won't fit on 160GB space.

Mind you, I got this laptop before I knew I would be editing and gaming a lot. So instead of upgrading, I'm thinking a desktop would be more suitable because I am such a heavy user.

But I am not such a technical user. I don't really know which specs are suitable for me. Like the noticeable difference between 2.5GHz and 2.7GHz, i5 and i7, 6750M and 6770M, and RAM.

My current laptop can't really handle playback rendering on After Effects at all, and I basically have to close everything apart from the program if I want to avoid the rainbow ball of fury so it doesn't crash. Also annoying is rendering on FCP. It takes AGES to render a few seconds.

So in terms of noticeable difference, e.g. under Spec 1 rendering x will take 5 minutes whereas under Spec 2 rendering x will take 2 minutes, what do you think would be good for my needs? I guess a start would be should I buy the base iMac and upgrade or the higher one and upgrade?

 

[Hellhammer]

Either the low-end or the ultimate 21.5" with the i7. Low-end is just fine but if the iMac will be used to make money, then it might be worth it to jump for the i7 as it supports HT which will speed up tasks that can take advantage of up to 8 threads (such as AE and the new Final Cut). If video editing is just a hobby, or your budget is limited, then the low-end is going to be fine.