Last week, MacRumors ran this post, which focused on an email exchange between a reader and Phil Schiller explaining the 16GB memory limitation on the MacBook Pro:
Question from David: The lack of a 32GB BTO option for the new MBPs raised some eyebrows and caused some concerns (me included). Does ~3GBps bandwidth to the SSD make this a moot issue? I.e. memory paging on a 16GB system is so fast that 32GB is not a significant improvement?
Schiller’s answer: Thank you for the email. It is a good question. To put 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. I hope you check out this new generation MacBook Pro, it really is an incredible system.
Over the weekend, this post hit the front page of Reddit’s Apple forum:
So, a lot of people have been disappointed at the lack of a 32gb option.
Apple’s statement is true, but lacks detail.
The true reason behind the lack of 32gb or ddr4 is intel. Skylake does not support LPDDR4 (LP for low power) ram. Kabylake is set to include support, but only for the U category of chips. So no LPDDR4 support for mobile until 2018 I think.
I’m no memory expert. This sound right? It jibes with Phil Schiller’s explanation, just more specific.
And the controller used for the LPDDR3 RAM that Apple is using supports a max off 16GB. Also, LPDDR3 at 2133Mhz isn’t supposed to exist, so is Apple overclocking their RAM?
This does not sound right. Skylake is more compatible with DDR4 and DDR3L, than with DDR3.
That is patently wrong. The Dell XPS 15 is supporting 32 GB DDR4 LV *(not LPDDR4 though) just fine using the very same CPU (i7-6700HQ Quad), and the battery life is absolutely comparable (around 9 hours using the model with the UHD panel and the 84 wH battery). I know, because I use exactly this machine daily (not that I like to, but Apple does not offer a choice).
If the MBP does not support it, it is because of choices they made. These may be legit (like RAM availability – not too many manufacturers offer the high density modules yet), or just plain cheapness. Since they even skimp on the power extension cord and one measly USB-adapter in the box (the minimum required to do just about anything with this new machine, since virtually no one will transfer data from a machine with TB3/USB-C), I go with the latter.
I am looking forward to getting mine, but Apple’s level of skimping at the customer’s expense becomes hard to bear.
Hi Dave, just a little thing, it’s jibes not gibes.
https://www.vocabulary.com/articles/chooseyourwords/gibe-jibe/
It’s completely correct, actually. Skylake has no LPDDR4 support.
It’s correct. Skylake supports DDR4, but NOT LPDDR4.
I did not say that. And nobody asked for LPDDR4, DDR4 works just fine.
Not if you want to deliver better battery life. I suspect more people prefer that over 32GB.
Thanks, James. Absolutely. And fixed. Appreciate it!
— Dave
You say to a person who specified they are running the exact same CPU in a Dell XPS 15 as in the new MacBook Pro 15″ with 32GB of DDR4 RAM (and UHD display) and getting –9 hours– of battery life.
Do you people READ the stuff you comment on?? Sheesh.
(And, for the record, before a bunch of other idiots start trying to spout off about LPDDR4, DDR4 consumes power roughly similar to LPDDR3, albeit a tiny bit more but not significantly so, but significantly lower than DDR3. The power consumption difference between 16B and 32GB of LPDDR3 or DDR4 is 8-10W. The TDP of the CPU is 28W for the i5 and 45W for the i7. I think most people who want 32GB of RAM would be willing to sacrifice an about ~1-1.5 hour of battery for it. They’d probably be OK with an extra 2 millimeter of thickness and a half-pound of weight too. Probably. They’re pros, it is important to them.)
To compare, the MacBook Pro gets 10 hours (Apple claims) of battery life using a 54.5-watt-hour battery vs. 9 hours using an 84-watt-hour battery in the Dell. That’s a very significant difference in power usage.
Obviously there are tradeoffs involved to get 32 GB of RAM. Apple wasn’t willing to sacrifice batter life and/or overall size & weight (for a larger battery) to support 32 GB. I’m not saying that’s the right choice (I would love to have the option of 32 GB), but Apple’s claim that supporting 32 GB would require more power is true.
Well, no idea where you’ve got this number from. Apple says the new 15″ model has a 76 Wh battery. That is only an approx. 10% difference, and we all know OS X is better at preserving battery power than Windows. So, in summary, the effect of the 32 GB non-LP DDR4 RAM is on the battery is pretty much irrelevant and Apple could have easily done the same thing. (The real life difference between DDR4 and LP DDR4 is maybe the equivalent of setting your screen turn-off time a minute shorter.)
And even if there is a minor difference, most “pro” users will use some pro applications – and pretty much none of these will run a whole day, no matter what you are using, so they will be plugged in most of the time anyhow. And some could definitely use that RAM. Since it cannot be upgraded later, Apple should offer more future-proof configurations. Everything else about that machine is, so dropping the ball on this one was clearly a mistake.
Oops, I was looking at the battery for the 13 inch. My bad.
Still, I wouldn’t say the battery life is “irrelevant”, a 10% difference is still significant. That’s a tradeoff that I, myself, would have gladly taken. Apple, for whatever reason decided to prioritize battery life over the option of adding 32 GB. I don’t agree with that, but it is a tradeoff, you can’t get both max battery life and max RAM. Something has to give.
My hope is that Apple sees a lot of this negative backlash and reacts by prioritizing performance & RAM increases in the next revision. I also hope that we don’t have to wait a year & a half for that next revision.