27" iMac Haswell i5 vs i7

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Level 1

90 points

27" iMac Haswell i5 vs i7

I'm finally going to upgrade from my '08 24" iMac to a new 27" iMac "dream machine" and need some professional advice. The heavy lifting will be for periodic video editing via Final Cut Pro, After Effects, etc.

Here's what I'm planning on:

RAM: 16GB 1600MHz DDR3 SDRAM
SSD: 512GB Flash Storage
GPU: NVIDIA GeForce GTX 780M 4GB GDDR5

Here's where I'm torn:

CPU: 3.4GHz Quad-core Intel Core i5, Turbo Boost up to 3.8GHz

OR

CPU: 3.5GHz Quad-core Intel Core i7, Turbo Boost up to 3.9GHz

In the past there seemed to be a greater difference between the CPU options, but now, the disparity doesn't seem as wide. I checked Intel's site and their bottom line:

"The Core i5-4670K has 33% less cache than the Core i7-4770K and no Hyper-Threading. The Core i7-4770K's Hyper-Threading feature helps by creating four additional virtual cores for a total of eight threads, which increases performance during multitasking procedures."

So I'm not sure which would be the most beneficial in my case, particularly during the "heavy lifting" stage.

I'm stretching my budget as it is but am willing spend the additional $200 for the i7 if it would really make a difference and it sounds like it might, but I'm hoping for some expert advice.

TIA!

iMac, OS X Mountain Lion

Posted on Sep 29, 2013 1:53 PM

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Answer 1

richsadams Author

Level 1

90 points

Sep 29, 2013 1:57 PM in response to richsadams

Sorry...this is the link describing the differences between the Haswell i5 and i7:

http://www.techpowerup.com/reviews/Intel/Core_i5_4670K_and_i7_4770K_Comparison/

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Answer 2

LowLuster

Level 6

12,105 points

Sep 29, 2013 2:19 PM in response to richsadams

None of the Newest iMacs have an i7 CPU. If you want an iMac with i7 you'll have to buy a leftover, before they run out of them, at an Apple store or authorized reseller or buy a Refurbished late 2012 from Apple. But in either of those cases you won't be able to customize it. You'll have to take whatever they have in stock. You can upgreade the RAM yourself but that is all you can upgrade.

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Answer 3

richsadams Author

Level 1

90 points

Sep 29, 2013 2:34 PM in response to LowLuster

LowLuster wrote:

None of the Newest iMacs have an i7 CPU. <snip>

Thanks, but it would seem so...

http://store.apple.com/us/configure/ME089LL/A

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Answer 4

LowLuster

Level 6

12,105 points

Sep 29, 2013 2:52 PM in response to richsadams

Sorry I missed that. I was looking at the tech specs and missed the light grey text below it that states you can get a i7.

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Answer 5

richsadams Author

Level 1

90 points

Sep 29, 2013 2:55 PM in response to LowLuster

No worries. Spending more than I did on my first new car I tend to go over the details with a fine-tooth comb! 😉

Still wondering if the additional $200 is worth it or not though.

Cheers!

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Answer 6

LowLuster

Level 6

12,105 points

Sep 29, 2013 3:00 PM in response to richsadams

For $200 I think not. Yes the i7 will be faster but not $200 faster IMHO.

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Answer 7

Sep 29, 2013 4:59 PM in response to richsadams

I would go with the 1GB fusion drive and get the I7 instead of the I5. The 128GB SSD part of the fusion drive is plenty big for the system and lots of apps. I use Photoshop, Lightroom and MS Office and they all load instantly. After getting my 27” with the fusion HD I could not get use to using my 13”MacBook Pro with a traditional HD anymore and installed a OWC SSD in it.

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Answer 8

richsadams Author

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90 points

Sep 29, 2013 6:04 PM in response to anthonyfromglen ellyn

anthonyfromglen ellyn wrote:

I would go with the 1GB fusion drive and get the I7 instead of the I5. The 128GB SSD part of the fusion drive is plenty big for the system and lots of apps. I use Photoshop, Lightroom and MS Office and they all load instantly. After getting my 27” with the fusion HD I could not get use to using my 13”MacBook Pro with a traditional HD anymore and installed a OWC SSD in it.

Thanks for the advice Anthony! Completely agree...having installed an SSD in my current iMac as well as using my MacBook Air w/SSD, jumping on a machine with a spinning hard drive seems like slo-mo!

My first intention was exactly as you suggest...a 1TB Fusion Drive. The difference between the 1TB Fusion Drive and a 500GB SSD is $300, so that would certainly pay for the i7 and leave a little money to spare. Hmmm...now I'm leaning Fusion...more food for thought! 🙂

I guess I'm still trying to determine if the additional cache and hyper-threading of the i7 will really have a noticeable impact on my video work, particularly rendering. I suspect that it will, but can't be sure. Hopefully someone with some specific first-hand knowledge in that arena will stumble on this and point me in the right direction.

Thanks again for the great advice!

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Answer 9

Sep 30, 2013 7:19 AM in response to richsadams

The closest comparable model for which there are Geekbench 2 benchmark results is the late 2012 27" iMac. You can see them using Mactracker, but the difference is (all 4 core options apparently)

i5, 2.9GHz 9197

i5, 3.2GHz 9535

i7, 3.4GHz 12884

So i7 would give you roughly 33% improvement over an i5 on a sample load. You may want to also look at the geekbench 3 results here:

http://browser.primatelabs.com/mac-benchmarks

That doesn't directly answer your question on how your 'heavy lifting' apps would perform, however, it's a good general benchmark on the CPU. It does not address how the GPU performs, and it is possible that your workload would be more heavily influenced by the choice of GPU than CPU.

I looked but could not find a recent benchark of Final Cut Pro on a recent imac. My suggestion would be, if possible, to take a sample to an Apple Store and run on one of their machines to see if you notice enough difference to want to 'spend the money.'

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Answer 10

Sep 30, 2013 8:08 AM in response to richsadams

Again, you are spending a lot of money here and of course you want it to use it more than a just a few years. I think the trade off here for the fusion + I7 beats out the 500GB SSD and I5. I'm very happy with the fusion drive. These new iMacs have the new faster connection for the fusion (and the SSD). I think what I have is blazing fast and the new fusion & SSD drives are 1.5x faster then my 1st generation fusion drive.

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Answer 11

richsadams Author

Level 1

90 points

Sep 30, 2013 8:27 AM in response to Bradford W. Miller

Thanks Bradford, excellent info and thanks for the link! I'm still wondering how much difference there would be in the applications I'm using, so heading over to the Apple store with a little project might be worthwhile. Not sure if they'd have FCP on two machines with different CPU's, but you never know.

I'm planning on getting the GPU upgrade. It has 4GB VRAM so that and more RAM should make the video work pretty fast, no matter which CPU I get (and am leaning toward the i7 now that's it's closer to my budget).

Agree with you and Anthony about the Fusion Drive over the SSD now. Although I use an external "scratch" drive for video projects, having the extra space would be welcome.

Cheers!

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Answer 12

richsadams Author

Level 1

90 points

Sep 30, 2013 8:36 AM in response to anthonyfromglen ellyn

Thanks again Anthony...as mentioned I think I'll take your and Bradford's advice and get the Fusion Drive. I was reading up on things and see that the new PCI Express-based flash storage has improved the Fusion Drive's response times by at least 50% over the 2012 Fusion setup. Nice.

One of my concerns (and why I was considering the SSD) is heat...knowing that the GPU will probably get pretty hot under a load, plus the CPU...adding a spinning HDD to the mix will raise the temps even more. Have you experienced things getting uncomfortably warm with your new iMac?

I'm starting to get into rarified Mac atmosphere now (dollars wise) and am wondering if the new Mac Pro might be an option. Wonder what it will cost? I'd want to spring for a Cinema Display so all-in-all I'm pretty sure that's beyond what I want to spend though. Wonder when they'll release it?

I've been very happy with my iMac however, so I'm pretty sure that's where I'll land.

Cheers!

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Answer 13

Sep 30, 2013 8:54 AM in response to richsadams

I would go for the I7. After Effects will take advantage of the Hyperthreading with it's "render multilpe frames simultaneously" option. Not sure about Final Cut.

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Answer 14

richsadams Author

Level 1

90 points

Sep 30, 2013 9:06 AM in response to peterfromatlanta

Thanks Peter...hyperthreading for AE will certainly be helpful. Leaning toward the i7 more and more now.

Cheers!

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Answer 15

Sep 30, 2013 9:30 AM in response to richsadams

BTW Rich, Here is the config I ordered last week....

27-inch iMac

• 3.5GHz Quad-core Intel Core i7, Turbo Boost up to 3.9GHz

• 8GB 1600MHz DDR3 SDRAM - 2X4GB

• 256GB Flash Storage

• NVIDIA GeForce GTX 780M 4GB GDDR5

I am replacing a 3 year old MBP that I used as a backup to my workstation. I will be adding a ram kit from OWC to reach 32GB. I originally ordered the imac with a 1TB fusion drive, then iFixit ( http://ifixit.org/5354/a-tale-of-two-new-imacs/ ) did a tear down and it was revealed that you will be able to add a sepereate SSD. I will go that route once the adapters come out. This is importatnt to me because I mostly use After Effects and it benefits greatly from have a seperate SSD for caching. I'm very excited to get this thing up and running!

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