or Connect
AppleInsider › Forums › Mac Hardware › Current Mac Hardware › Struggling over which 27-inch iMac to get
New Posts  All Forums:Forum Nav:

Struggling over which 27-inch iMac to get

post #1 of 4
Thread Starter 
Hi guys,

Am hoping to get a 27-inch iMac shortly to add to my 2007 MB.

Am slightly struggling over which one to get.

From the looks of benchmarks, there is very little difference at all between the relative performance of the 2.7 and 3.1 GHz chips (in fact, on some single core tasks, the 2.7 is actually faster!). So it really comes down to how important it is to have the better graphics card.

I'm not really a big gamer, and probably won't become one. However, I would like to get into X-Plane, so having good enough performance on that would be a bonus. But the difference in price between the two machines leads me to wonder whether I would get by adequately with the 2.7 GHz cheaper machine.

Notwithstanding gaming differences, does the better graphics card in the 3.1 GHz model help in any way with performance for video editing, After Effects etc, which I will be using a lot? I know that CS5.5 is only meant to properly harness certain nVidia cards, but would the difference in iMac Radeon cards affect me in any way?

I look forward to any replies, and thank you in advance to anyone who takes time to do so

BFBM
post #2 of 4
Quote:
Originally Posted by bluefunkybassman View Post

Notwithstanding gaming differences, does the better graphics card in the 3.1 GHz model help in any way with performance for video editing, After Effects etc, which I will be using a lot? I know that CS5.5 is only meant to properly harness certain nVidia cards, but would the difference in iMac Radeon cards affect me in any way?

You can directly compare the performance of the cards here:

http://www.notebookcheck.net/AMD-Rad...M.43955.0.html
http://www.notebookcheck.net/AMD-Rad...M.43077.0.html

The 6970M has double the amount of processors, although lower clocked. That alone should make it ~85% faster and it shows in some benchmarks e.g 3DMark06 - 10500 vs 17500.

For the majority of games, both will play them on high quality so it won't really make a difference. Applications like After Effects and Final Cut don't use the GPU for much at all but when they do, the 1.3TFLOPs of the 6970M will hold a good advantage over the 696GFLOPs of the 6770M and the extra VRAM is good too. This will only really be apparent in apps like Motion though.

For $300, I wouldn't bother with it. If screen size isn't too important either, you'd be better off with the 2.8GHz i7 21.5" with the 6770M.

27" i5 = http://browse.geekbench.ca/geekbench2/view/427183 = 7900
21.5" i7 = http://browse.geekbench.ca/geekbench2/view/426970 = 10400

The i7s are hyperthreaded so they show up as 8-cores. You will see more of a benefit from this encoding video and rendering in AE.

I would say though, the 21.5" screen feels quite small and cramped. The 27" is very spacious for video editing. Ideally, I wish they'd make a 24" @ 2200 x 1240 or thereabouts and use it across the lineup but they obviously try to balance CPU cost and screen cost in some models.

21.5" 2.8GHz i7 = fastest CPU, decent GPU = $1699
27" 2.7GHz i5 = slowest CPU, decent GPU, big screen = $1699
27" 3.1GHz i5 = slightly better CPU, fastest GPU, big screen = $1999
post #3 of 4
Thread Starter 
Very many thanks for your comprehensive reply, Marvin. That gives me a lot to chew on. I think I agree with you that I'd prefer the 27". I don't think I could afford the i7, so I'll take a look at your links re video cards and decide which i5 to get. The price difference is pretty big just for a better gfx card....
post #4 of 4
Thread Starter 
Just thought I would tell you what I actually did in the end.....

I noticed that Apple had the previous generation top-end BTO iMac, the i7 2.93, in the refurb store for £1289. This has now disappeared, so one really needs to strike while the iron's hot.

This was far too good an opportunity to miss out on, as it beats the current best i5 by some margin performance-wise, and even the graphics performance is far better than the current 2.7GHz i5 I was looking at.

Should arrive tomorrow, hopefully :-)
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Current Mac Hardware
AppleInsider › Forums › Mac Hardware › Current Mac Hardware › Struggling over which 27-inch iMac to get