What to Expect from the Core M Processor in the New MacBook [Updated]

Image credit: Apple

Apple's new MacBook, to be released on April 10, is compact, low in weight, and full of new features. But will that low power Core M processor have enough computing punch for most users? I want to take a first, high-level look at the Core M processor and how it compares to other Apple notebooks, new and old.


I'll go out on a limb and surmise that many Apple customers are decidedly undecided about the CPU in the new MacBook. This Intel Core M processor (Core M-5Y70) processor uses a 14 nm design process, the 'Broadwell" architecture. It has a very low Thermal Design Power (TDP) of just 4.5 watts. That allows it to work without a fan, relying instead on passive cooling. {Update: Checking Apple specs showing Turbo Boost at 2.4 GHz, it seems the actual processor in the base 1.1 GHz MacBook model is actually the M-5Y31. ]

That low power design, combined with the MacBook's three color options, a Force Touch trackpad, a simpler design when it comes to ports, a Retina display (2304 x 1440) and a newly designed "butterfly" key action, makes for an attractive, lightweight package.

Even so, many prospective buyers may be wrestling with the notion that this new Core M processor may not have enough horespower to accomplish the tasks they may have in mind for it. It certainly isn't in the class of Intel's i3, and i5 processors, and it's very far from the i7 option (2.2 GHz, Turbo Boost to 3.2 GHz) available in Apple's entry level MacBook Air.

Decision Points

In addition to the basic technical specifications of the Core M, one has to take into account three other important factors.

  1. Intel's technology moves along smartly. It may well be that the Core M in the new MacBook has equal or more power than the three or four year old MacBook Air you're using now. You'll gain the features of the MacBook without losing too much, if any, CPU and graphics power compared to what you've been using.
  2. Your intended usage for the new MacBook should realistically match the class of the product. For example, this small gem of a MacBook shouldn't be thought of as a Mac to run advanced 3D rendering, Photoshop or Xcode at blazing speeds or run multiple virtual machines in Parallels Desktop at the same time. [Check back for an update.] If one has in mind writing, email, Twitter, Instagram, music, web surfing, Keynote/Pages/Numbers, and Skype, for example, then one can probably be confident, based on the data published so far, that the MacBook is up to the job.
  3. Do you need it right now ?

Related to #1 above, Intel says that, compared to the late 2013 Core i5 (4302Y), the Core M is 47 percent faster in 3D graphics and 82 percent better in video conversion. (The i5-4302Y has been used in tablet PCs like the HP Pro x2 612 at 1.6 GHz, a rather low end product.)

Intel Core M layout. Image credit: Intel.

While the CPU makers always pick the most favorable benchmarks, there's no denying that you have to decide if you want to compare Apple's new MacBook against what you could have in a 2015 MacBook Air (or Pro) or against what you've been using for the last few years. The latter case, the idea would be to take advantage of new features, better display and lower weight.

In terms of pricing, a current 13-inch MacBook Air with 8 GB RAM, 256 GB flash storage and a Core i5 at 1.6 GHz (base) will cost exactly the same as a base MacBook, US$1299. You'll have more ports in the MBA and a bit more power, but it'll be missing the Retina display, better keyboard and the Force Touch trackpad.

Which brings up point #3. No doubt, the new technology of the Broadwell 14 nm process will percolate into the i3/i5/i7 line. And so, if one is looking for, say, a fanless MacBook Air in the next 6-12 months, it would seem to be a possibility.

Next page: Core M Architecture and Geekbench 3 Scores.

Page 2 - What to Expect from the Core M Processor


Core M Architecture

Like most of the MacBook CPUs, the Core M has two cores and the ability to run four threads. However, when I look at the processor data from Intel and compare it to even the four year old MacBook Air with an i5-2557M, I noted several missing Intel features. This is something to dig into later, but is beyond the scope of this early introduction.

Excerpt from Intel's spec page. Note ability to access 16 GB RAM.
Apple doesn't offer that option.


Of course Apple's marketing philosophy is that every new product is fantastic. We never see admonitions or constraints, such as "Don't try to do advanced computations that require very a very high end processor." So it's really left to the customer to properly size up this new Macbook, recognize its position in the hierarchy of Apple notebooks, and be ready to accept some limits.

GeekBench 3 Scores

Finally, for another comparison aspect, here's some Geekbench 3 data from Primate labs. I've listed approximate, average numbers frm all the tests reported. Note the Core M was running at 1.3 GHz on a Lenovo Yoga 3 Pro (80HE) not 1.1 GHz. {Update: some actual benchmarks have since been posted for the MacBook by MacRumors. They've been added below.]

                        Single Core    Multi-core   Note
MacBook/M-5Y31, 1.1 GHz       1924           4038   dual core   
Lenovo/M-5Y70, 1.3 GHz       ~2500          ~4300   dual core
2014 MBA, i5/4260U, 1.4 GHz  ~2500          ~4700   dual core
2014 MBP, i7/4980HQ,2.8 GHz  ~3600         ~13000   quad core

Digital Trends wrote, "The Intel Core M 5Y70 is clearly not built for strenuous workloads. If you keep multi-tasking under control, though, it should at least make for a passable computing experience."


A first look at the data for the Core M suggests that while it's no powerhouse and the 5300 graphics won't dazzle, it appears that that Apple's new MacBook will have performance comparable to older MacBook Airs that it might replace.

Finally, if this new MacBook is treated as a highly portable Apple notebook and kept in perspective, it looks to be a good choice. However, for those users who want to hang onto every last port, still keep the system weight under 3 pounds, and yet extract every erg of performance from a high end MacBook Air, this new MacBook probably won't satisfy. That's why, after all, Apple has a range of notebook choices.