Comparing Mac hardware—amortized cost and approx. performance gains

Hey team! This is a long one for those of you who like armchair-advising about hardware purchases.

I realize this poor dead horse has been thoroughly beaten (oof, what an awful cliché, really), but I thought I’d share some thinking (and get your valuable feedback) on justifying rationalizing deciding on a potential Mac upgrade in the near future.

I have a 2015 MacBook Pro (MBP). While I cherish it, it recently failed me. I was working on a project for a client (editing a systems map like this, if you’re curious) and the MBP started stalling. I imagine the challenge was rendering the numerous elements of the map at high resolution (5K). Anyway, some functions it just couldn’t do.

I thought I was ruined, because of course it failed at the final step just before the deadline. Fortunately, my wife’s two-ish year old 27" iMac was in the next room. I loaded the same map up and working on it was buttery and quick.

So. Between that and the fact that the MBP’s fans are constantly trying to keep the temperature below 70°C, I am itching for an upgrade.

Pending whatever happens at WWDC, I’m looking at a Mac mini or a 27" iMac. In order to figure out which to go for, I thought I’d calculate [1] the approximate amortized cost (per year) of a purchase (found in column five below), and [2] the approximate performance gains each computer might have over my MBP .

I’ve managed to keep my MBP for five years, so that’s the number of years I’d hope to keep this next device (at least).

At first, I used’s data to grab the Geekbench scores for each device. Then I realized that these numbers wouldn’t take my configuration choices into account. So, I went to Geekbench proper, sought out recent scores uploaded by users with the configurations I’d want, and used that data instead.

Note: costs are in Canadian dollars.

Price Estimated selling value after [Years] Actual cost Years Amortized cost per year Geekbench 4 SC 64 vs. MBP Geekbench 4 SC 64 Geekbench 4 MC 64 vs. MBP Geekbench 4 MC
MacBook Pro 2015 $3187.54 $800.00 $2387.54 5 $477.51 100% 4363 100% 14533
Mac Mini $2463.00 $800.00 $1663.00 5 $332.60 140% 6107 189% 27397
27” iMac 2019 $4798.00 $1500.00 $3298.00 5 $659.60 138% 6022 234% 34016

The takeaway: It looks like I’d have to pay about double for my choice of 27" iMac, but there’d be no real performance gains on single-core operations vs. the Mac mini. I don’t think I do a lot of multi-core work, so the 45% performance gain on the iMac in that category doesn’t really matter to me.

Granted, the iMac comes with a display, but I have a great one already (and I don’t think I’d run two 5K displays next to each other on a smallish desk…).

One surprise: these gains are not as big as I’d have thought. “Only” 40% better performance… is that a lot, really?

Thoughts? Any other comparisons you’d run? Any deep flaws in my logic? Anything else to consider?

(Maybe all of this will be blown up with WWDC and ARM Macs anyhow!)

Edit: the specs I’m looking at for the mini are the 3.2Ghz 6-core i7 with 32gb of RAM and either 512gb or 1tb of storage.

Since you are transitioning from an MBP, you can still cart the Mac mini to a different location when needed. You cannot cart around the iMac (as easily).


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We won’t see the release of ARM Macs but were are likely to learn more about them which could influence buying decisions now. Plus new machines are rumored to come out soon too. so yes, I think the question is premature.

I would not consider an iMac Pro unless I absolutely needed the power today and didn’t mind new models coming out later in the year. (I think there’s a good likelihood that Apple will consolidate iMac models and use the same new design for all iMac & iMac Pros.) If I needed to replace a machine right now I’d get a refurbished iMac nonPro and resell/trade it in when new hardware is announced in the fall.

As a point of comparison, I don’t think people who bought the last Motorola Macs before the PowerPC switch would have been too happy with their machines four years later, same for those who had the last G5 PowerMacs four years into the Intel transition. So I’d rethink any consideration that you’d get 5 solid, delighted years’ worth of use out of an iMac Pro purchased today.

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Thanks to you both!

@DrJJWMac: great point. I may keep the MBP, if only for use at conferences (especially for editing/presenting), but I should reconsider my costs with this in mind.

@bowline: I don’t think this changes your arguments, but note that that’s an iMac, not an iMac Pro, in my list. (Canadian pricing for an iMac Pro starts at $6,300.) I will definitely check out the refurbs though.

I mentioned the iMac Pro because you’d said you were considering a 27" iMac Pro. Not a fan of the price/performance of today’s older-tech model.

@bowline Aha, sorry, that was a mistype on my part. The 2019 iMac seems much better (and still cheaper) than the iMac Pro, somehow.

I took a look at refurb models currently available. There happened to be a Mac Pro for ~$7,000, but no Geekbench 4 scores are available for Mac Pros as far as I could find. So, I’ve updated my table with Geekbench 5 scores. Oddly the performance gains over my MBP are much more modest. Moreover, the Mac Pro’s scores seem embarrassingly low. I must be missing something about how these scores are calculated.

Table 2. (costs in CAD, non-refurbished items are education pricing.)

Price Estimated selling value after [Years] Actual cost Years Amortized cost per year Geekbench 5 SC 64 vs. MBP Geekbench 5 SC 64 Geekbench 5 MC 64 vs. MBP Geekbench 5 MC 64 Geekbench 4 SC 64 vs. MBP Geekbench 4 SC 64 Geekbench 4 MC 64 vs. MBP Geekbench 4 MC
MacBook Pro 2015 $3187.54 $800.00 $2387.54 5 $477.51 1 952 1 2926 100% 4363 100% 14533
Mac Mini 2020 $2463.00 $800.00 $1663.00 5 $332.60 117% 1110 185% 5427 140% 6107 189% 27397
27” iMac 2019 $4798.00 $1500.00 $3298.00 5 $659.60 129% 1232 304% 8908 138% 6022 234% 34016
27” iMac 2019 Refurb $3479.00 $1200.00 $2279.00 5 $455.80 129% 1232 304% 8908 140% 6088 228% 33155
27” iMac Pro 2017 refurb $5349.00 $1200.00 $4149.00 5 $829.80 121% 1150 292% 8540 123% 5376 237% 34440
Mac Pro refurb $6689.00 $1500.00 $5189.00 5 $1037.80 111% 1059 280% 8191 0% 0%

Well, I’m just chronicling at this point, but this is odd. I added my wife’s 2017 iMac scores to the chart… and my MBP outperforms it, technically speaking. By a fair amount:

Geekbench 5 SC 64 vs. MBP Geekbench 5 SC 64 Geekbench 5 MC 64 vs. MBP Geekbench 5 MC 64
15" MacBook Pro 2015 100% 952 100% 2926
Compare with 27" iMac 2017 85% 806 101% 2969

…so it must be that my MacBook Pro’s stalls are caused by some environmental factor, likely the fact that it’s driving a 5K display through a dongle.

Hrm. This is unfortunate—maybe a new computer isn’t the right solution, but getting rid of the display is.

Or perhaps you just need a more powerful dongle.

Does your MBP have an i7 and the iMac an i5?


Do you have more detail about your most intensive work?

For example, that systems map you linked to (which is so pleasing to the eye), is the editing done in the browser? If so, which one? Are you doing any work more intense than that?

Otherwise, according to Marco Arment, most options for Macs from Apple have (+/-) 40% performance improvements in single core performance. (Even lower comparing chips for a single model).

You also didn’t mention how much RAM your current set up has. Depending on what you’re doing this could be the issue moreso than the CPU. Potentially, having a beefier GPU could be the answer you’re looking for as well.

JJW: I hadn’t thought about the fact that dongles have their own specs. Hmm. And yes, MBP = i7 (quad-core 2.8 GHz). iMac = i5 (quad-core 3.4 GHz).

@dustinknopoff Good questions.

The systems map you looked at is probably the most intense, and yes, it’s all in-browser. Safari and Chrome faired similarly in performance (I tried switching to Chrome before switching to the iMac). I’ve also experienced some slowdowns using/navigating big databases in DEVONthink and exploring large numbers of papers in Bookends.

This MBP has 16 GB of 1600 MHz RAM, compared to 8 GB of 2400 MHz RAM in the iMac.
MBP = 2 GB dedicated graphics memory in an AMD Radeon R9 M370X, iMac = 4 GB dedicated graphics memory in a Radeon Pro 570.

The loss of a dedicated graphics card in the Mac mini is my biggest fear, but I suppose I can just run an eGPU and it’ll still be a cheaper upgrade than jumping to an iMac.

Maybe consider 32GB of RAM in a Mac mini and an eGPU if mini can’t handle your workflow?

It’s my understanding that browsers are pretty RAM hungry (all of them, Chrome’s just the worst) and that depending on the browser, they use the GPU and CPU in different intensities for rendering.

(I was certain that the <canvas> element is all GPU rendered but haven’t found any articles proving that).

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When I did something of this comparison last year, I settled on a few factors that were important, with single-core speed being the most important. And no matter how I sliced it and diced it, I couldn’t make the premium for other setups over a Mac mini make sense.

I also was nervous about not having a dedicated GPU, as I do a lot of CAD and photo editing (but no video editing.) But after getting a mini, this turned out to not be an issue for my workflow. Even though I’d be ready to get an eGPU, I can’t see how it would help, other than drive some future 5K monitor more easily.

Perhaps the one factor or assumption that you might question is holding on to a machine for 5 years –only because this seems to be an inflection point in Mac hardware history.

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No worries. I think think that at this point, days away from WWDC, your post is still premature.

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I love my Mac Mini and it was certainly the right purchase for me, but it does seem to run hot (granted, I do live in Thailand), and it seems to struggle to power my devices all the time.
I suspect there are bottlenecks in the system that the iMac may be better for.
My Mini runs cooler than my MBP still.

What I’m saying is that as you move up from MPB to Mini to Imac I think continuous throughout and thermal’s and whatnot get better.
If I needed GPU, which I think you do I would have gone for an iMac I think. As I didn’t really and I had a monitor, I got the far better value Mini.

Just my feeling, anyway.

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Thanks, @dustinknopoff. Indeed, that seems like the right path. (And yes, too bad a variety of essential apps are web- or electron-based these days…)

@Timo / @GraemeS — Thanks for that firsthand experience! As @bowline pointed out, I should clearly wait a bit. But listen, people—the heart wants what it wants! And right now, that’s a little quiet black box…

Oddly, today I’m able to work with my client’s map with little trouble. I must have been running something in the background that was eating up resources the other day.

The current iteration, since you’re all so invested, looks a little like this (:warning: large image by the way; and the text’s obscured on purpose).

I dunno what that is, but it looks neat.


I too have a 2015 MBP with the same specs as yours.

Last year sometime my power supply started acting up, so I took it to a local Mac repair shop and they told me to get a new supply from Amazon. Not available in Canada from Apple.

Anyways, while it was in the shop they mentioned that I was eligible for a couple of FREE replacements. They sent it off to a local Apple repair shop for me and they put in a brand new keyboard AND a brand new Retina display. I was shocked to say the least.

The downside is that now I have to wait a lot longer before I can get a new MBP (wife, budget, etc.)

You might want to see if you are eligible for any recalls that Apple may have made.

Good luck!
Larry Wilson


Thanks, @Larry_Wilson—actually essentially my whole machine was refreshed just last year. I brought it in for a checkup because the battery health had declined and, thanks to AppleCare+, they decided to replace basically all of the internals. (One bonus to the non-repairable design of these devices, I suppose!)

@Timo It is a model of the complex chains of cause and effect that interact to cause zoonotic pandemics!

Well, WWDC 2020 has come and gone, and I think @bowline’s probably right about a 2-3 year lifespan for a machine purchased today. I’m gonna be desperate for an Apple Silicon chip once they’re past the first generation.

So, I think a cheaper purchase now will be better in the long run. It probably doesn’t make sense to wait for the to-be-announced machines and buy a new one at full price if I plan on upgrading again when Silicon becomes standard. It may be a Mac mini after all!

FYI Steve jobs announced the transition to Intel in June 2005, said it would take about two years (sound familiar?) but the transition was actually completed 14 months later. Snow Leopard was the last macOS version to support PowerPC, and perhaps because of that it has substantial longevity and was supported/updated 2009-2011.

(Conceivably Apple could do something similar if a geographic area like the EU has a mandate on OS support to match their hardware support requirement.)

So the lifetime could conceivably be more than 3 years, but practically - with the introduction of USB4/Thunderbolt4 likely only on ARM machines, plus the addition of AI cores (as in A-series chips used in iOS), plus the promise of dramatic speed increases unlike what we’ve seen the last several years with Intel - people, especially MacPowerUsers™, won’t want to hold onto new hardware for longer (or even that long).

I’m currently a bit at a personal impasse as I learn more about the potential power of the new ARM hardware. I’ve long been planning to get a new 27" iMac this fall to replace my 2017 Retina iMac, but if the power of an ARM/iMac is is the ballpark of Intel, then given the promised (though not fully explained) ability to run iOS apps on Big Sur/ARM, I might well consider going that route earlier than planned. (The main complication for me is that the rumor is that we’ll see a 24" ARM iMac only in 2020, and I really prefer the larger Retina screen.)


If you’re not starved for power or stuck with an end-of-lifed machine, I would recommend to wait for the ARM Mac form factor you’re looking for. Of course, Intel Macs are going to be supported for several years, but their days, even still long, are clearly numbered. If you like to buy a powerful machine to last long, this doesn’t seem like the time for that kind of bet.

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