Tech —

The 2015 MacBook previews a future that’s not quite here

Review: This laptop is defined by the features it doesn't have.

Internals and performance: Somewhere between a 2011 and 2012 MacBook Air

The short version

The MacBook has the approximate CPU speed of a 2011 MacBook Air, the GPU speed of a 2012 MacBook Air, and the storage speed of a 2013 MacBook Air. It won't set any records, but it will do just about everything an Air will.

The long version

As more systems with Intel’s Core M processor have come to market, it’s become more apparent just how much variance there is from system to system. These chips can have TDP values of 3.5W, 4.5W, and 6W, and the value a particular OEM decides to use has a larger-than-usual effect on the kind of performance you’ll get.

Apple is using a Core M-5Y31 CPU and it says the base clock speed is 1.1GHz, which tells us that the company is using the chip’s maximum TDP value of 6W. That means the MacBook looks better than some other Core M laptops, particularly Lenovo’s Yoga 3 Pro. Core M is still no match for the Broadwell-U Core i5 and i7 chips in the latest MacBook Airs and Pros, but CPU and GPU performance are both respectable.

Our original ballpark assessment was that the MacBook would be more-or-less comparable in performance to a 2012 MacBook Air, and now that we’ve had more time to test, we can say that our estimates weren’t too far off.

The base model MacBook posts CPU performance numbers that are just north of a 2011 MacBook Air. If you need a little more CPU power, Apple offers both a Core M-5Y51 and 5Y71 as upgrade options. We’ll try to get the 5Y71 version in for some additional testing, but we’d be surprised if either could much exceed the base performance of a 2012 Air.

If you’re already frustrated by the lack of noticeable improvement in CPU performance between the 2013, 2014, and 2015 Airs, the new MacBook will only disappoint you. But the upside is that the MacBook’s CPU is usable for most of the same stuff that a MacBook Air’s CPU is usable for. I edited photos, edited and exported my podcast, and did all my regular work on the MacBook without yearning for the extra oomph of my Core i7 2013 MacBook Air.

Another interesting thing to note, though we didn't include it on these charts: the MacBook’s multi-core CPU performance is nearly identical to that of the iPad Air 2. The A8X still has lower single-threaded performance—it needs a third core to match the dual-core Core M—but we’ve gotten to the point where top-end ARM chips and low-power Intel chips have very similar power usage and performance characteristics.

The Intel HD 5300 GPU’s results are a mix of good and bad. On the one hand, its raw performance is slightly better than a 2012 MacBook Air’s, which is better news than we have on the CPU side. On the other hand, that GPU is tasked with driving a display with many more pixels than any MacBook Air, which can lead to the mixed Retina scaling performance we talked about earlier.

That being said, light gaming and 3D work on the MacBook is possible if you keep your expectations reasonable. I played a smooth game of Minecraft in full screen mode, and I did it without the fan whine that you get when you try to do the same thing with a MacBook Air of any vintage. The 13-inch MacBook Pro remains the best compromise between CPU/GPU speed and size/weight, though.

Like all other 2013, 2014, and 2015 MacBooks, the Retina MacBook’s SSD uses a PCI Express 2.0 interface rather than the older, slower SATA interface. The difference in the 2015 MacBooks is how many PCIe lanes the SSD is connected to, which directly affects how much bandwidth is available to the drive. The 13-inch MacBook Air and Pro use four PCIe 2.0 lanes, while the 11-inch Air and the Retina MacBook use two lanes.

Update: The MacBook's controller does use four PCIe 2.0 lanes, though its peak performance still doesn't match what you'll get from a 13-inch Pro or Air.

This means that the MacBook’s peak storage performance will be similar to what you’d get from the first wave of PCIe Macs in 2013 or 2014. This is still great performance, since most PC makers continue to use SATA even in their flagship Broadwell Ultrabooks. The MacBook never feels less than zippy when you’re booting or loading programs or moving files around. But as you can see from the read speeds here, giving these SSDs four lanes still improves the performance quite a bit.

If you’re wondering why the MacBook’s write performance is better than the 13-inch Air or Pro’s, it’s because the MacBook comes with a 256GB SSD by default rather than a 128GB SSD. More capacity generally means more NAND chips are being used, which means that the controller can write data to more places simultaneously. This is called “interleaving” and it obviously has a big impact on performance. Upgrade the Air or Pro to a 256GB or 512GB drive and we suspect they would still be able to outperform the MacBook.

Battery life

Apple promises "up to nine hours” of wireless Web usage, and our Wi-Fi Web browsing test suggests that this number should be attainable in light usage—we got around 11 hours with the screen brightness set to 200 nits. That’s still several hours short of what the 13-inch Air and Pro, but it’s far and away better than the Core M-based PCs we’ve seen so far (the Yoga 3 Pro and HP’s EliteBook 1020).

It fares less well in our WebGL test, which keeps the CPU and GPU active with a light but continuous workload. Here it lasts around three and a half hours, better than the Pro but far short of the 2015 Air.

In real-world usage, the MacBook’s battery will easily get you through an eight-hour workday, but it doesn’t feel as luxurious as the battery in recent 13-inch Airs. We’d expect the move to be easier to get used to if you’re coming from an older Air or an 11-inch model, all of which have lesser battery life.

The design of the MacBook, its port layout, and its power adapter all suggest a more iPhone- or iPad-like usage model for the MacBook, one where you use it most of the day and then plug it in at night. But OS X is not iOS. Part of the reason why iOS devices have the battery life that they do is that Apple maintains strict control over what apps can do and what tasks can run in the background, even in this post-iOS 8 era. OS X is not nearly so locked down; it's part of the platform's appeal. But that also means you’re going to run apps and plugins that are bad citizens, things like the Flash player that suck down power but are nonetheless still required for many sites. My iPad will sometimes go days between charges, but I don’t see this being possible for most MacBook users.

You must to comment.

Channel Ars Technica