Looking for some last-minute advice on iMac 2011 purchase

[seasonofpassage]

I'm buying from the Apple Refurb site, and I've basically narrowed it down to two options. I'm going to be using it mostly for 3D filmmaking using Autodesk (Maya/Mudbox/Softimage), so I know the processing power is going to be a factor. I don't plan on really gaming on it besides "Sims 2" (ahh, 2004), so I don't know how heavily the GPU difference should weigh into it. The two different builds are:

1) 27", 2.7 GHz i5, 6770M / 512 MB. Price is $1,525 after tax.
2) 27", 3.1 GHz i5, 6970M / 1 GB. Price is $1,800 after tax.

Looking at it from a pure spec standpoint, the 6970M model is clearly what I'd want to go with, but I'm wondering if the upgrade in the GPU and processor is worth the $275 increase for what I plan on using it for. The $1,800 is about my ceiling on what I can realistically spend at the moment. I'm also aware that this generation is about halfway through its usual lifespan, and so there's a small part of me that just wants to wait until a possible Ivy Bridge update--but there's always gonna be something new around the corner.

Any advice is greatly appreciated. Thanks in advance.

 

[apw100]

Man, thats a tough call. Honestly, neither of those is going to be great for heavy 3D work.
You should really consider getting a 21" iMac with the i7 if you want the most performance at your price point. The i7 will be much faster than the i5 for what you are doing. Sure, the display isn't as big, but you can always add another cheap monitor to use for your softwares' toolbars and stuff and use the iMac's display for modeling and color sensitive work.
If that isn't an option, I advise you to save up for a while and get the 27" i7 iMac.

Option 1- 21" i7 iMac w/8GB (don't upgrade from Apple, buy from Newegg and install it yourself), and a cheap secondary monitor.

Option 2- Save your pennies and buy the 27" i7

 

[seasonofpassage]

Thanks, apw100. So, what you're advising me to do is look at these two options (at least as far as the refurb store):

1) 21.5", 2.8 GHz i7, 6770M/512 for $1,525 again (after tax), or...

2), 27", 3.4 GHz i7, 6970M, 1GB for $1,981 after tax.

The 27" is a bit higher than I wanted to go, price-wise, but if the benefits outweigh the costs then it's definitely something to consider. So now there's a gap of $456 between the two, with the difference being the screen size and the GPU upgrade. Thoughts?

 

[apw100]

If you are concerned about price, go with the 21" i7 iMac. Either way, I'd go with the i7 option. The i5's are quad core but they lack Hyperthreading, which allows for 4 virtual cores. This can really make a difference in performance with software that can utilize multiple cores. You should see a significant speed increase in rendering.
You will also benefit a lot by adding RAM. You can purchase 16GB(4x4GB) from NewEgg for about $100. Or, just buy two 2GB sticks to add to the ones that are already there for a total of 8GB.
Neither of the GPU's are exactly pro caliber, in fact, they are "mobile" versions meant for laptops. That being said, the 1GB of memory will probably be helpful.

Budget option- 21" i7(2.93ghz) iMac(2011)
http://store.apple.com/us/product/G0M50LL/A?mco=MjMwNDYzOTY

Ideal option- 27" i7(3.4ghz) iMac(2011)
http://store.apple.com/us/product/FD063LL/A?mco=MjMxMjQzNTQ

 

[seasonofpassage]

Just bought the 21.5" i7. And yeah, I was planning on boosting the RAM to 12 GB by going to NewEgg...good to know that's advisable. Thanks for the help. It's taking too long to process, though. I want it in my hands now.

 

[4zuresky]

imac 2011 21.5" i7

I'd recommend looking at geekbench for numbers.
http://www.primatelabs.ca/geekbench/mac-benchmarks/index.html If you wonder how well you can render things, look up the iMac you want and it should give you a number to the right. The higher the number, the better! And apparently, the 21.5" i7 renders WAY faster than the base model 27" i5. Good thing you bought the 21.5" i7