Suitable iMac Option / System

If the budget is there and you want the most power out of your machine for the long run I’d say your best bet is to max it out. 3.4GHz i7 and the top end GPU.

What confuses me though, and also would make for adjustments to my suggestion, is why must it match your current systems? No matter what you buy it will be better, there’s no real denying that. Nothing saying you can’t still use the old ones, maybe just use them less.

If it is the case that they don’t need to be that similar I would also suggest getting more than 8GB of RAM (although definitely buy third party, keep the default 4GB apple RAM and put more in yourself). 8GB is good but if your software is very intensive (I know little about it I’ll admit) than you’d be better off with 12 or 16GB of RAM at least.

For CAD software I would recommend the 6970m at minimum, and preferably you should wait for the likely, but not promised or announced, upgraded models coming in about 3 weeks.

This post is timely for me. I am also an architect using ArchiCad, looking for a new iMac (and waiting impatiently for the re-fresh). Current machine is a 24" 3.06 C2D, and I find it slow for CAD modelling, although fine for everything else.

In any case I would recommend the 27" for maximum screen real estate (not sure why you are considering a 21"?).

I'm also curious as too how much CAD work and modelling relies on processor speed versus Graphic speed - can anyone clarify so we can choose the most cost effective solution?

How is the 21.5" screen working for you? If it's fine, then buying the 2011 21.5" will definitely work for you too and will be the less expensive option. I agree that you should configure any iMac with the least possible RAM and upgrade the RAM yourself after the purchase. That will save you a couple hundred dollars. I also agree that you might want to consider 16GB RAM. After market it is only about $125. Apple will charge you $100 to go from 4GB to 8GB and $300 to go from 4GB to 16GB.

From time to time Apple also offers refurb'd iMacs that come with the same warranty as a new iMac. You can generally save your self a few dollars doing that. There is only one 21.5" refurb'd iMac available now but several 27" iMacs. You can check them out on the Apple Store.

You will definitely introduce screen envy into your business if you select the 27" iMac ... gorgeous screen. Be careful. LOL.

Go i7. For multi-threaded apps, like CS5 and archicad etc, the i7 will run double the processing.

27" is worth it for architects. Mandatory really. You could buy a Retina powerbook though and add a third party IPS screen, or even an Apple one, but the apple would cost you $300 more. but if you want to take your work to a client, or your work home, the Retina powerbooks are faster than all the iMac range available at the moment.

Duckett said:

REPLY: I apologize and have failed to mention that our iMac in-house models are 21.5" inch and would prefer to keep this setup throughout the office, if possible. We would also like keep the cost down if possible. I have mentioned to match, as our present system runs sufficiently / smoothly, as is, with our architectural software. My main hesitation is with the graphics card, as I have noticed that they are now using a mobile / integrated card instead of what was previously specified. I could be wrong in what I have stated, is this case? or would the AMD Radeon HD 6770M suffice, match or better what is present within our in-house system.

ALSO: Would it be wise to upgrade the systems processer to an i7 on our final decision, or will the i5 suffice?

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I wouldn’t be worried if I were you about the GPU. It may be mobile but the newer GPU will be able to offer you the power you’re looking for. The macs in my university’s main mac lab are 2010 models (as I believes yours is) and have the highest end GPU available at the time in an iMac. However my 2011 iMac GPU has better performance and Benchmark scores. They may be mobile but they are mighty. I do believe though that you’d get more use out of the 27” GPU’s because of their VRAM which is at least double that of the 21.5” models. Combined with 16GB of RAM (which, as mentioned, would be best) they would run CAD software with ease; certainly better than what you have now.

On the CPU front I do believe the i5 would be strong enough for your purposes but the CPU isn’t like RAM or (if adventurous enough) an HDD that can be replaced. Since you state that you want the computers to last at least 5 years I would say your best bet is to get a quad core i7, regardless of which model you choose (21.5" or 27”) I upgraded the CPU in my iMac and don’t regret it one bit when I’m rendering in After Effects.

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Melbourne Park said:

Go i7. For multi-threaded apps, like CS5 and archicad etc, the i7 will run double the processing.

27" is worth it for architects. Mandatory really. You could buy a Retina powerbook though and add a third party IPS screen, or even an Apple one, but the apple would cost you $300 more. but if you want to take your work to a client, or your work home, the Retina powerbooks are faster than all the iMac range available at the moment.

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Just to correct, you mean Retina Macbooks. The powerbook no longer exists.

Duckett said:

REPLY: I apologize and have failed to mention that our iMac in-house models are 21.5" inch and would prefer to keep this setup throughout the office, if possible. We would also like keep the cost down if possible. I have mentioned to match, as our present system runs sufficiently / smoothly, as is, with our architectural software. My main hesitation is with the graphics card, as I have noticed that they are now using a mobile / integrated card instead of what was previously specified. I could be wrong in what I have stated, is this case? or would the AMD Radeon HD 6770M suffice, match or better what is present within our in-house system.

ALSO: Would it be wise to upgrade the systems processer to an i7 on our final decision, or will the i5 suffice?

Click to expand...

My opinion stands. You should go for the 6970m at minimum. If you would like to stay at 21.5", then I would definitely recommend holding out for a few weeks and seeing what the upgrade is (assuming it comes).

The 2011 "mobile" GPUs are pretty good. 2012 seems to be the year that, at least at the top end, they can compete with mid-range desktop performance.

The 2012 21.5" iMac is, in my estimation, likely to have an Nvidia GTX 660M. That performs about 80% better than the AMD HD 6770m in the 2011 model. The AMD card will likely be able to get the job done, but the Nvidia will be much better at it and will, barring component failure, probably last you two extra years longer. The gap in performance from 2011 to 2012 in "mobile" cards is much wider than usual.

I don't believe the work you are doing is likely to see much benefit from using the i7 over the i5 CPU.

Duckett said:

I appreciate your prompt response. Are you able elaborate on which version of the AMD Radeon HD 6970M we should obtain, the 1GB or 2GB GPU? Also, would the 6970M match or better the new Nvidia GTX 660M graphics cards? If comparable. Could you please provide an explanation to why the i7 would have not much benefit over the i5? Regards.

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The newer Nvidia cards would still out-perform the 6970m just not as vastly as they would the 6770m. Problem is that it’s speculation at this point as no one really knows what the iMacs will have in them.

As far as your VRAM goes, for your line of work, more is better. I know when I start 3D rendering on my GPU with 512MB of VRAM it definitely slows down. Not to an unacceptable level and it is a worse GPU than the 6970m but the point is still valid. If you have the coin you would certainly get use out of maxing the GPU.

Duckett said:

I appreciate your prompt response. Are you able elaborate on which version of the AMD Radeon HD 6970M we should obtain, the 1GB or 2GB GPU? Also, would the 6970M match or better the new Nvidia GTX 660M graphics cards? If comparable. Could you please provide an explanation to why the i7 would have not much benefit over the i5? Regards.

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The 27" iMac has more pixels to push around. If you were getting this year's model with a 6970m at native resolution, it would be worth it to get the 2GB. Nothing over 2GB has proven to be worthwhile yet; the top 2012 iMac should have the Nvidia GTX 680M which is capable of 4GB, but as far as I can tell getting 4GB is a waste.

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The AMD 6970m is actually about 20% better than the Nvidia 660M, and was a fantastic card for 2011. (I will note here that Adobe products sometimes perform better on Nvidia vs. AMD than standardized benchmarks would indicate.) At the top end the new 27" should have the Nvidia 680M, which again improves performance by about 80-100% over the 6970m.

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The primary advantage of the i7 CPU is "Hyperthreading". Hyperthreading makes it look like you have twice as many CPU cores as you actually have. To take advantage of this, you need either:
1) Extremely CPU-intensive applications that were written specifically to take advantage of multiple threads, or
2) The need to run many different applications at once.

As far as I can tell the applications you use are more GPU-intensive than CPU-intensive. So unless you need many background renderings going simultaneously, the i7 won't have a noticeable benefit.

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AcesHigh87 said:

The newer Nvidia cards would still out-perform the 6970m just not as vastly as they would the 6770m. Problem is that it’s speculation at this point as no one really knows what the iMacs will have in them.

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The benchmark actually suggests otherwise. The 2011 6970m isn't bested by anything in 2012 from Nvidia short of the 675M (which is the 2011 580M). There's just a HUGE jump from this level to AMD's 7970m and Nvidia's 680M.

Your second point is correct, though. I'm just making educated guesses about what cards will be in the 2012 iMacs.