MacBook Pro Touch Bar 007

As you know, Apple’s limited the new MacBook Pro to a maximum of sixteen gigabytes of RAM. Truth be told, no Mac notebook thus far has permitted customers to double the system RAM to a whopping thirty-two gigabytes though many MacBook Pro fans seem to have expected just that as an option.

As we told you, Apple on its part did acknowledge that it’d decided against giving the new Pro 32GB RAM because doing so would have decreased the notebook’s battery life.

The statement is true, but lacks detail.

The Loop’s Dave Mark points us to a more technical explanation for why you cannot outfit your brand spanking new MacBook Pro with 32GB RAM.

TL;DR: Skylake platform powering the new MacBook Pro supports DDR4 RAM, but not its LPDDR4 variant that optimizes energy consumption—Apple isn’t lying when it argues that doubling the Pro’s RAM would have a negative impact on battery life.

Here’s an interesting excerpt from a Reddit post (edited for clarity):

The true reason behind the lack of 32GB RAM on the new MacBook Pro is Intel. Skylake chips do not support LPDDR4 RAM. Kaby Lake is set to include support, but only for the U category of chips. So no LPDDR4 support for mobile until 2018 I think.

LPDDR4 stands for a low-power version of DDR4 RAM.

Skylake, of course, is Intel’s chip microarchitecture that powers the Pro. Kaby Lake is the name of Intel’s seventh-generation microarchitecture that was unveiled in August.

“U category” of chips denotes low-power versions of Intel processors meant for ultra-thin notebooks like the MacBook Air and the twelve-inch MacBook. These chips are typically slower than their non-U counterparts, but conserver more power.

In other words, Skylake lacks hardware support for power-sipping RAM chips that could let Apple engineer a 32GB Mac notebook that didn’t sacrifice battery life. The new Pro uses a faster 2133MHz LPDDR3 RAM that consumes more power than the slower 1600 MHz RAM in the previous-generation.

hello again event various macbook pro

You could say that Reddit’s RAM explanation is patently wrong and cite Dell’s XPS 15 as an example, which has the same quad-core Intel Core i7-6700HQ chip from Intel like the new Pro yet packs in 32GB RAM. However, it’s important to note that a) Kaby Lake is required to support DDR4 RAM and B) the Dell machine supports the power-hungrier DDR4 LV RAM technology rather than its low-power LPDDR4 counterpart.

An alleged response from Apple’s marketing boss Phil Schiller to a question from a concerned user about the Pro’s RAM situation clarifies that putting more than 16GB of fast RAM into a notebook design “at this time would require a memory system that consumes much more power and wouldn’t be efficient enough for a notebook.”

The new Pro delivers the same all-day battery life like its predecessor, meaning up to ten hours of wireless web or iTunes movie playback for both 13 and 15-inch models.

Source: Reddit via The Loop

  • ravinigga

    Was it not lpddr3?

  • SixBanananas

    Thats what I found on wiki:
    Dell XPS 15: DDR4 at 2133 MT/s = 1.2V
    Kaby Lake: Low Power DDR4 at 3200 MT/s (LPDDR3) = 1.1V or by Samsung at 0.6V
    Old MBP: Low Power DDR3 at 1600 MT/s (LPDDR3) = 1.2V
    New MBP: Low Power DDR3 at 2133 MT/s (LPDDR3) = 1.8V

    I don’t get Apples decision or I’m clearly misinformed…

    • Mike

      The voltage is not the only thing that affect power consumption. LPDDR has many other technics to save power compare to regular DDR. For example, regular LPDDR3 (1.2V) use ten times less power when idle compare to DDR3 (1.5V). Idle power consumption is quite important for portable device such as laptop.

  • Rob Jansen

    Why would you need 32gb for that weak processor? I have 16gb in my monster of a pc and don’t even come close to needing more.

    • Golicza Alpár

      But when you hook up multiple 4K screens and run multiple applications on them, you will run out of ram.

    • iPilya

      I keep hearing people talk about the “weak” CPU. Which mobile CPU should they have used? Kaby Lake (4-core) is not released yet.

    • erhhung

      If you use Windows natively you probably wouldn’t require (as many) VMs, but if you like Mac as a base system and need to run Windows and Linux VMs at work, you’d hit the 16GB ceiling really quickly.

  • Braheem Hazeem III

    16gb in my x99 6 core CPU desktop PC, which I never fully use. Why would a weak laptop need more than that?

  • Marcus

    Apple should’ve just made the new MacBook Pro’s twice as thick so that they could put in a bigger battery. The fact that they keep making their MacBook’s thinner and thinner baffles me. There is no need.

    • Reg Guy

      LOL…clearly someone who doesn’t hump laptops through airports!

      • Jumanji

        lmao heaven forbid you carry something 4.5 pounds instead of 4. If you’re having a hard time carrying that much weight maybe you should stay home.

      • Marcus

        I go to the airport several times a year with my laptop. It can be annoying to carry around, but it’s not that much of an inconvenience. Apple should’ve just kept thin MacBook Air’s and then they should’ve made thick MacBook Pro’s.

      • iPilya

        @marcus_413:disqus the key here is “several times a year”. You are definitely not a traveler. Try saying several times a week. But lets take the airport aspect out of the equation. A person can also reference needing to go client premises several times a week.

        But if we return back to the Airport aspect… you are limited to the size of battery. While Apple could up the size (would have been nice), but they cannot upsize it all that much. What I don’t know is if Apple maxed out the batter size, could they still have gotten 10 hrs using 32GB of DDR4?

    • mike480

      Agreed, there was no need to go any thinner lighter on the new MBP as the previous generation weight and size is not an issue and I carry my laptop through an airport every single week. more ram to run my VM’s would have been so welcome and I was practically expecting it.

      • Marcus

        Strongly agree. I don’t mind carrying around a laptop that’s 5, 6, or 7 pounds. I want something powerful.

      • foljs

        Maybe carry a desktop then?

  • mike480

    I would have gladly sacrificed some battery life for 32GB ram. While it would be awesome if I got to sit in a park and work all day with no outlet, that just isn’t reality. I don’t need 10 hours battery life and I would argue that the folks who need 10 hours battery number less than us who need 32GB ram.

    • foljs

      Everybody can use more battery time. Very few have a need for 32GB RAM.