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Comment by uptown | Hacker News Reader

> "models now are 16gb of ram only (can someone explain this one?)"

"Apple told me MBP maxes out at 16GB RAM because LPDDR3 limit is 16GB/chip; Apple uses it because of performance/energy ratio."

https://twitter.com/DanFrakes/status/791754757404626944

So basically, it needed to be thin and light ... because, Apple ... which limits the size of the battery. And more RAM would consume more energy, requiring the device to potentially be thicker and heavier to accommodate a larger battery in order to meet their runtime expectations.

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If it was all about battery savings, then why not use DDR4? DDR4 is more power efficient [1]

[1] http://www.memcon.com/pdfs/proceedings2013/track2/Designing_...

Cost. Margins. Their current price point is already an increase. Not sure what using DDR4 would do to that but presumably newer tech translates to higher costs.

Your link compares DDR4 against DDR3, but you should be comparing DDR4 against LPDDR3.

Why not LPDDR4 against LPDDR3? LPDDR4 is also more efficient and has better density.

Skylake does not support LPDDR4, nor does Kaby Lake (except with their ultra-low power chips).

I don't think we're going to see 32 GB RAM in the ultrabook category until LPDDR4 is supported by Intel in their mobile-class processors.

Edit: AnandTech suggests that LPDDR3 is 25-30% more power efficient than DDR4. (http://www.anandtech.com/show/6326/additional-details-on-mic...)

That might be so, but the macbook air is the ultrabook series and the mac book pro should be the work horse series.

I have a Dell Precision 5510 that supports up to 32GB of RAM and also has Skylake Mobile Xeon. Alas, it is plagued with tons of issues.

~~Older MBPs were thicker and could support 32GB. So Apple both cut away a little bit thickness for no reason, and then used that as an excuse to drop max RAM support? Something smells odd about that conclusion.~~

EDIT: No 32GB MBP ever existed. My bad.

They never could support 32GB of RAM AFAIK.

There was a MBP that supported 32 GB of RAM ?

No if there was I'd still be using it.

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