iMac chips

I have been configuring iMacs on the Apple website trying to figure out which would be the best replacement for my current MBP. I wanted 16GB of memory and the basic quad core i7 chip. I can, of course, do that on the Apple site, but I have not found that configuration on pre-built machine. The closest I could find had a 3.3GHz quad core i5 chip and a 4.0GHz i7. The latter seems like overkill to me.

The main processing I do is photo editing using tools like CaptureOne, Lightroom and Photoshop/Affinity Photo. I do not know if there would be enough difference between a quad core i5 and a quad core i7, both about the same chip speed, to notice when doing normal (not commercial) photo editing. I understand that the graphics card is also important but I know next to nothing about graphics cards except that the memory is really important.

The Retina i7 has the Radeon M2900X as its basic card and the non-Retina i5 does not list a graphics card (which I suppose means that it uses on-board graphics or perhaps a basic graphics card). So my question basically is whether the i5 would be noticeably slower than the i7 doing photo editing for home photos. Any help would be appreciated.

NOTE: The above refers to the 27" iMac. The choices for the 21" are much less varied and there is no graphics card options. The 21" chip offerings are a 2.9GHz quad core i5 and a 3.1GHz i7 quad core. The same question would apply to these.

MikeFromMesa said:

I have been configuring iMacs on the Apple website trying to figure out which would be the best replacement for my current MBP.

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We would first need to know what the specs are on your MBP so we would know the best replacement. Of course I'm guessing you want more than just a replacement…you probably want a replacement that's better than the MBP. Depending on the model MBP you have (and it's specs)…probably any new iMac will be much better.

Can we assuming you are only looking at 27" iMac's…or 21" iMac's as well?

MikeFromMesa said:

I do not know if there would be enough difference between a quad core i5 and a quad core i7, both about the same chip speed…

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I think that you need to be more specific as to what exact configurations you're considering (exact CPU type & speed)…so we can better evaluate. What I can say is (depending on what you are considering). The i7 quad-core config's can be around 30% faster than the i5 CPU's. And…the i7's support "hyperthreading" (two process's/CPU). Which means an i7 based iMac can have up to 8 simultaneous threads/process's (4 real & 4 virtual)…compared to 4 threads/process's for the quad-core i5 CPU's.

MikeFromMesa said:

(I understand that the graphics card is also important but I know next to nothing about graphics cards except that the memory is really important.

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More & more computing tasks need good graphics hardware to be done well. Some tasks require a lot of CPU power…and some computing tasks require a lot of GPU (graphics) power. The computing industry over the past few years (I feel) has made much more progress in the area of graphics than with CPU's (graphics performance increases vs. CPU performance increases). Which may reflect the need for better & better graphics with today's computer demands.

MikeFromMesa said:

The Retina i7 has the Radeon M2900X as its basic card and the non-Retina i5 does not list a graphics card (which I suppose means that it uses on-board graphics).

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If we're talking the non-retina 27" iMac…it lists the NVIDIA GEForce GT 755M with 1gig video memory as it's graphic's hardware.

But again. Please supply us with the exact specs of each setup you are considering. And then we can probably give better opinions/evaluations.

- Nick

pigoo3 said:

Please supply us with the exact specs of each setup you are considering. And then we can probably give better opinions/evaluations.

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Yes. It is quite clear to me that I was not specific enough about both what I am currently using and what I am considering buying.

I am currently using an early 2013 MacBook Pro Retina, 16GB of RAM, 2.7GHz i7 with 512GB SSD using an NVIDIA GeForce GT 650M 1024 MB graphics card. The machine is in very good shape and is more than fast enough although it is true that I would want a faster machine if I decided to upgrade. I am currently using an external Dell 24" UltraSharp monitor with the MBP because of its matte screen and my issue with high gloss monitors. The only reason I am considering upgrading is that my wife wants to get rid of her Windows laptop and it seemed like a reasonable idea to give her my MBP as all she does is browse the internet and then I would need a new machine.

I have looked at both 21" and 27" iMacs as a replacement for the MBP. The Mac Minis only support dual core chips and I believe would be annoyingly slow for me after the MBP. I would try the iMac with its glossy screen by using an anti-glare covering and, if that worked, I would use it like that. If not, I would use the machine as a computer and presumably hook it up to my 24" Dell monitor. That would imply that the 21" would be large enough if I am going to be using an external monitor but if the anti-glare covering worked well I would prefer the 27" as I think the 24" screen is a bit small.

Since I would want something at least as capable as my MBP my minimum configuration is 16GB of RAM and 512GB of disc although 32GB of RAM and a 1TB fusion drive would probably be better. The minimum that I have set for any purchase is thus 16GB of RAM and 1TB fusion drive. Given that, here are my pre-built options:

21" iMac

2.7GHz i5, 16GB RAM, 1 TB fusion drive, integrated IRIS graphics,
2.9GHz i5, 16GB RAM, 1 TB fusion drive, integrated IRIS graphics,
3.1GHz i7, 16GB RAM, 1 TB fusion drive, NVIDIA GeForce GT 750M Graphics with 1 GB of memory

27" iMac Retina

3.3GHz i5, 16GB RAM, 1 TB fusion drive, AMD Radeon M290 GPU with 2 GB of memory
3.5GHz i5, 16GB RAM, 1 TB fusion drive, AMD Radeon M295X GPU with 4 GB of memory

The vendor I have been looking at (B&H) also has non-Retina pre-builts, but they are all a bit old (2013) and I have not included them in this list. If I can get a good anti-glare screen I would get the 27" but if not, then the 21" would be fine, but I would want a machine at least as fast as my current MBP. I know I can configure a specific machine according to my wishes on the Apple website but I am currently trying to find one pre-configured on a vendor website like B&H, Adorama or MacMall.

I hope this has been specific enough. What I not trying to find out which is the fastest. That is surely the 3.5GHz 27" iMac, but I am trying to find out which I could expect to be at least as fast as my current MBP and which machines would would be close to each other in speed so as to not make much difference. I read recently that the iMac can be configured so well that it is only about 10% less capable than a basic level Mac Pro so it seems worth looking at what might be a good solution. I would consider the Mac Pro if it were not so expensive and so close in performance to the much-less-expensive iMac (based on the benchmarks I have seen online).

Again, thank you for any help you can provide.

MikeFromMesa said:

I am currently using an external Dell 24" UltraSharp monitor with the MBP because of its matte screen and my issue with high gloss monitors.

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Thanks for all the info/details…but yes…we are back to the "high gloss" issue. How are you going to deal with this purchasing an iMac? Sounded to me that a Mac-Mini with the monitor you choose (probably the 24" Dell you have) was the way to go.

Edit. Nevermind…just saw the detail about using an anti-glare covering.

- Nick

Can you possibly narrow things down between a 21" and 27" iMac? This is probably a very logical place to start…since the difference in display size is significant…and is usually one of the major considerations when someone is purchasing an iMac.

Plus (from a CPU performance standpoint)…there is probably at least one 21" and one 27" iMac in the choices provided that would "fit the bill" in terms of similar performance to your current MBP.

- Nick

pigoo3 said:

Can you possibly narrow things down between a 21" and 27" iMac? This is probably a very logical place to start…since the difference in display size is significant…and is usually one of the major considerations when someone is purchasing an iMac.

Plus (from a CPU performance standpoint)…there is probably at least one 21" and one 27" iMac in the choices provided that would "fit the bill" in terms of similar performance to your current MBP.

- Nick

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One of the things you mentioned that I did not know was that the i5 chips were only 1 thread per core. All of my expectations were that any quad core i5 or i7 would give me 8 threads so it is significant to any decision of mine that I know that. I always knew my lack of hardware experience would be a problem for me one day.

Based on the i5/i7 chip difference I should add one more line to the 27" iMac and that would be

4.0GHz i7, 16GB RAM, 1 TB fusion drive, AMD Radeon M295X GPU with 4 GB of memory.

My choice between the 21 and 27 inch iMacs would depend upon whether or not I could get a decent anti-glare screen. If not, then I have no preference since I would be using my current monitor. If so, then I would prefer the 27" as I think the 21" monitor is a bit small, considering that I have it set up at the end of my sofa and that I sit about 4 feet from the screen.

I guess I would like to know which machine configurations were at least as fast as my current MBP both for normal photo editing (one image at a time) and for batch processing (typically sending 100-200 images for processing from raw to jpg). The second is less important than the first as I can wait for batch processing. I just want the editing to be smooth and easy. Typically that would involve both a workflow tool like CaptureOne (or Optics Pro) and an external editor like Photoshop (or Affinity Photo) and using external plugins as well.

Two things:

1. Apple is rumored (repeat: RUMORED) to be bringing out a 21.5-inch iMac (the less upgradable after purchase one) with a new 4K display in a week or so. Don't know how much stock to put in this, but the rumor doesn't make much sense at this point (same rez as the 27-inch 5K, there aren't any 21.5-inch 4K displays being made at present, would probably necessitate a price increase, so ... could be true but ...)

2. I'm not an expert on this, but there is VERY likely to be a "cost-value horizon" on video cards from a photography point of view, ie a 4GB video card is not 4x better than 1GB video card. Video cards with large amounts of RAM are designed for 3D/gaming/video type work; 2D stuff doesn't benefit much from them beyond a certain point, but someone more knowledgable than I would have to weigh in to determine what that point would be.

No one with any information about which of the iMac configurations I listed would be at least as fast as my MBP?

MikeFromMesa said:

No one with any information about which of the iMac configurations I listed would be at least as fast as my MBP?

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I can give you a CPU benchmark comparison of the various setups mentioned. GPU (video) benchmark comparisons are harder to come by. But generally speaking…the newer the GPU and the more video ram is has…GENERALLY the better it performs.

CPU benchmarks:

Current MBP = 12851

21" iMac:

2.7GHz i5 = 10310
2.9GHz i5 = 10875
3.1GHz i7 = 14159

27" iMac Retina:

3.3GHz i5 = 11785
3.5GHz i5 = 11958
4.0GHz i7 = 16558

- Nick

pigoo3 said:

I can give you a CPU benchmark comparison of the various setups mentioned. GPU (video) benchmark comparisons are harder to come by. But generally speaking…the newer the GPU and the more video ram is has…GENERALLY the better it performs.

CPU benchmarks:

Current MBP = 12851

21" iMac:

2.7GHz i5 = 10310
2.9GHz i5 = 10875
3.1GHz i7 = 14159

27" iMac Retina:

3.3GHz i5 = 11785
3.5GHz i5 = 11958
4.0GHz i7 = 16558

- Nick

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Thank you. That is a big help. Can you point me to where you got these so I can check some other configurations?

MikeFromMesa said:

Thank you. That is a big help. Can you point me to where you got these so I can check some other configurations?

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www.everymac.com

It's good to bear in mind that CPU performance is (a) not related to GPU performance and (b) not the sole or even best measure of how well a computer will perform in the real world. Just as a quick example, a computer with an SSD and lots of RAM will both "feel" faster and BE faster than one with the same CPU and GPU but very little RAM and a spinning disk.