Friday, November 10, 2023

8 GB of Unified Memory

Tim Hardwick:

Starting at $1,599, the 14-inch M3 MacBook Pro comes with 8GB of unified memory. That makes it $300 more expensive than the $1,299 starting price of the now-discontinued M2 13-inch MacBook Pro with 8GB. Users can opt for 16GB or 24GB at checkout, but these configuration options cost an extra $200 and $400 at purchase, respectively, and cannot be upgraded at a later date because of Apple’s unified memory architecture.


In a recent interview with Chinese ML engineer and content creator Lin YilYi, Apple’s VP of worldwide product marketing Bob Borchers has directly responded to this criticism.

Bob Borchers:

Comparing our memory to other system’s memory actually isn’t equivalent, because of the fact that we have such an efficient use of memory, and we use memory compression, and we have a unified memory architecture.

Actually, 8GB on an M3 MacBook Pro is probably analogous to 16GB on other systems. We just happen to be able to use it much more efficiently. And so what I would say is I would have people come in and try what they want to do on their systems, and they will I think see incredible performance.

You could make the case that the performance of certain tasks with 8 GB of RAM is good, but his statement goes way beyond that, and I don’t think the reasoning is sound.

It’s not clear to me what “efficient” is meant to refer to here. One could argue that macOS is less efficient with memory since it no longer runs in 32-bit mode. Maybe it’s a reference to Dynamic Caching, but that doesn’t seem like it would have much effect on memory use for common apps.

Memory compression has been available in macOS for a long time. I’ve used 8 GB and 16 GB systems with and without it and have no doubt that real RAM is better. Citing memory compression also doesn’t make sense because it’s a constant. The old M2 MacBook Pro also had memory compression. So does Windows.

The unified memory architecture does not seem like a technology to help stretch RAM. Rather, it means that some of that 8 GB will be used like VRAM and not available to apps or to the system.

William Gallagher (Hacker News):

A core claim of Apple’s is that this improved design means Mac need less RAM than they did.

The 8 GB M3 MacBook Pro is more expensive than the 16 GB M2 MacBook Pro was, and I’m not aware of any change in the M3 that would make up for that.


The thing we should be mad about are the prices. They’re charging $200 or more for each step-up in RAM. I understand that their RAM is integrated and special, but an 8GB stick of SD RAM for a PC is like $30. $100 might be understandable, but $200 is obscene.

The storage is even worse. Even the M3 MAX defaults to 1TB of storage. To upgrade to 4TB is $1000. A Samsung 990 Pro M2 SSD with 4TB of storage is under $300. I understand the apple storage is different, and that justifies some markup, but over a 300% markup is absurd.

Jason Cross (Hacker News):

It should probably not be a controversial opinion that, in late 2023 (and surely through most of 2024), one should not sell a pricey “Pro” computer with only 8GB of RAM. And yet here we are.


Apple has a long history of providing less RAM than it should for the price of its laptops and overcharging to get more, but it’s reached ridiculous proportions. The cheapest standard configuration with more than 8GB of RAM is 2 grand! The cheapest MacBook Pro you can configure with more than 8GB is $1,800!


Not that Windows laptops and Macs are directly comparable, but comparably-priced Microsoft Surface, HP Envy, Alienware, Dell XP, and Lenovo Thinkpad laptops all have 16GB of RAM or more, standard. You can spend all day mired in laptop configurations (and I have) but the bottom line is this: 16GB is standard at prices over $1,000 even in laptops with premium displays and other high-end features.

Tim Hardwick (Hacker News):

Perhaps unsurprisingly, Yuryev saw significant performance improvements across the board using the 16GB machine under both middling and heavier workloads. The 8GB model suffered double-digit losses in Cinebench benchmarks, and took several minutes longer to complete photo-merging jobs in Photoshop as well as media exports in Final Cut and Adobe Lightroom Classic.

These tests were conducted as single operations with nothing else running, but also repeated with browser tabs, YouTube videos, spreadsheets, emails, and the like, open in the background to simulate typical real-world multi-tasking scenarios. As expected, the performance gap between the two machines widened further as the 8GB increasingly relied on its SSD swap file, while all-round responsiveness took a hit. Yuryev even reported crashes on the 8GB model during Blender rendering and a Final Cut export.

How about comparing the 8 GB M3 to the 16 GB M2?


15 Comments RSS · Twitter · Mastodon

Apple has a history of selling some base Mac models with unusable specs.
Not too long ago, laptops with 256 GB of SSD that were essentially full out of the box.
They had that base iMac with spinning drive and horrible CPU.
Now these “Pro” system with 8 GB of RAM.

I get it, they are trying to hit some magic price point for marketing reasons. But the problem is that less informed customers buy these machines nobody should be buying and get a terrible experience. They really need to make base configurations ok and upgrades not outrageous.

I'm looking forward to all the upcoming performance comparisons.

It will be interesting to see how the different ram configs perform compared to each other.

"But the problem is that less informed customers buy these machines nobody should be buying and get a terrible experience."

I think the Apple event was a total success.

I'm quickly becoming scared of purchasing a MacBook Pro M3 as I don't understand from the early reviews whether this is just an organic upgrade to the M2 versions or a scam.

I guess I will wait till January to see what the feedback is from real users and decide whether to finally move to Apple Silicon based Mac or not.

The upgrade prices for RAM and SSD are totally out of control. I was looking into buying the M2 mini recently as a replacement for my 2017 5K iMac. As an absolute minimum I need 16GB RAM and 512GB SSD (though 1TB would be the sane choice). To go from the base model to the above-mentioned config I'd have to pay 70% extra. BTO models are discounted far less in the marketplace, and I don't think this is a coincidence.

This is making me so mad, that I dread giving them my money. I'd rather stick to the Intel iMac, even though I can't use the latest and greatest macOS on it. On the plus side, the iMac has a much nicer screen than the LG screen I was going to use for the Mac mini.

By the way, I think I would be much less mad if they bumped the price of the base mode by say 200 EUR, but equipped with more RAM and more drive space. It would be much more palatable than the situation right now.

On the 8GB/16GB comparison. The claim that Macs are much more efficient with memory always seemed like BS to me. I don't pretend to understand how memory management works exactly in modern computer architectures. But the fact alone, that the memory is shared between the CPU and the GPU, should raise eyebrows.

Also, using AI/ML/LLM locally seems to require a lot of RAM. That is not boding well for the usefulness of base Mac computers in the near future. I'm not sure Apples marketing department has taken this into account sufficiently.

>I'm quickly becoming scared of purchasing a MacBook Pro M3 as I don't understand from the early reviews whether this is just an organic upgrade to the M2 versions or a scam.

Scam is a strong word, IMHO.

Do I think Apple's BTO prices for RAM and SSD are too high, and that a four-figure Mac with "Pro" in its name shouldn't come with 8 GiB RAM in 2023? And that Borchers's claim is a tiny bit exaggerated? Or that Ternus's claim that the Pro now starts at a cheaper entry point is sort of true but also sort of misleading? Yes.

Is the M3 upgrade a scam, though? No. It's a decent upgrade over the M2, stronger in some areas (GPU, e-cores) than others. And a more complicated story in the M3 Pro vs. M1/M2 Pro — fewer p-cores, more e-cores, so CPU performance isn't up that much, but battery life / eat / noise should improve. I'm torn on how much of this 1) an attempt to upsell people towards the Max (I really wish there were a Max variant with fewer GPU cores, because they'd be idling for me), 2) a correction of relatively weaker battery life (the M1 Pro had just two e-cores, and it shows), 3) hands tied due to TSMC yields.

But looking at it from a distance, we're 36 months into the era of shipping ARM Macs, and seeing decent performance gains with every generations, while power consumption (and therefore heat and noise) is holding more or less steady.

It's not a big upgrade from the M2, but the M2 isn't that old (heck, the M2 Pro and Max were released _this January_). Most people have a Mac purchase cycle of more like 3-5 years, and if you compare these machines to 2018-20 Macs? They're quite good.

Hardik Panjwani

Yup. Given the “courage” of the fruit company in skating to where the puck is going, the RAM thing seems dumb. The newer chips and unified memory help but it’s always better to be future proofed.

I mean, the marketing benefit alone (see how our competitors suck on RAM) should be enough to push higher sales that should offset the cost of bumping minimum specs.

The other thing is that many people will end up with minimum specs as they won’t change defaults, especially when buying online. Others will overdo it as they don’t know enough to optimize specs for their use case.

Definitely a place where improvement is warranted. Maybe do a small 3-5 question quiz on the website during the buying process to figure what specs to recommend to the buyer, then use that data to optimize the minimum specs a few years down the road.

I’ve had an M1 mini for a few months, with 8GB of RAM.

On a few occasions I’ve actually received “out of memory” error alert panels.

I don’t think I’ve seen those before in 20+ years of using OS X.

@Jon I get those, too, even with a lot more RAM. I don’t understand why it can’t use swap.

So, how are we supposed to buy a new Mac with an adequate amount of non-upgradeable memory, given that video memory is stolen (er, "allocated") from the "unified memory" pool?

In anticipation of needing a new machine, I'm starting to track and log my memory usage hourly with vm_stat, to get an idea of what my daily workload needs, but how am I supposed to translate this, plus video memory, to unified memory? Add 4GB? 8GB? More? Less? Apple only says "Just get as much memory as you can," which of course, means: "If in doubt, Give Us Lots More Money."

I don't want to shell out major bucks for a new Mac just to have its SSD destroyed by constant swapping, because there's enough RAM for my apps, but not enough to be able to see what I'm doing on screen. Not to mention that going from 24GB to 32GB requires a CPU, or even model, upgrade, which further inflates the cost.

By creating Apple Silicon, Apple has designed their Mac lineup to extract as much money as possible in every way, through cynical product design, FUD, and exorbitant pricing.

I am not some kind of mythical PRO-hero who has the resources to just spend whatever without a thought and lives and dies by video-export benchmarks (who seems to be Apple's target audience anymore).

How absolutely infuriating and disappointing this is. Plenty of computers for Pros, and, "Oh, OK, here's a computer for all the rest of you. It looks like a Fisher-Price toy. Ain't it cute? Oh, a laptop? Sure. Here. It has 2 ports. That's all we got. And no 27" iMac for you. Lotsa luck. Want an AppleCare sub with that?"


Clearly 8Gb != 16Gb, whatever the architecture, for tasks such as machine learning: the size of a floating point number does not magically halve on a Mac. Indeed, unified memory access means your screen and texture data is also in that 8Gb.

I can see an argument for it in terms of normal apps/webpages. They have been growing disgustingly large. If many customers have small Macs, there is some pressure on developers to keep memory usage down. And that saves money in the long term also on phones. But it's a bit ridiculous for pro-tools. I was given 8Gb Mac for work, and had to use slack. I ended up writing an applescript to kill it every so often, to keep the computer useable.

There are two ways I know of that Apple Silicon Macs can be “more efficient” than comparable machines with the same amount of RAM:

1) the RAM and the rest of the SoC are fast enough to make up for some speed hits, in perception at least, and
2) the flash is fast enough that the system can afford to keep fewer “clean” pages (library code, etc) resident, so it can evict clean pages more readily and use more RAM for other purposes, and just page back in as needed.

I believe that 8GB is therefore enough for some people. But more RAM is still better — my last purchase was a 64GB machine and I’d not go lower for my workload.

I got 8GB M1 Air as my first Apple Silicon mac, testing Apple's claims about 8GB being enough and returned it after two days of use with Xcode and browser with many tabs.

I have been expecting the SSD to be fast enough to make the swap almost unnoticeable, but the opposite was true:

- when switching the apps, the swapping delay was definitely large enough to matter, eg. 1-3 seconds
- and I quickly found out that having to swap isn't the assumption the MacOS has been built for, so during the swap, almost whole system locked up

Zone Of Tech couldn't get their test video to export on the M3 Base with 8GB of RAM, it kept running out memory and then failing or crashing.

Androids soon will have 32 GB of RAM. Take that as an example of in-efficiency.

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