Upgradable memory in future Apple Silicon chips

[leman]

For laptops, zero chance we will see upgradeable memory. However, there is a decent chance that Apple will allow upgradeable memory for Mac Pro.

Intel Mac Pros can go up to 1.5TB. There is no way Apple is going to solder on 1.5TB. And Apple needs to match the Intel memory capacity so Apple Silicon doesn't look inferior.

Apple has a patent on a multi-level RAM system:

Apple Patents Multi-Level Hybrid Memory Subsystem

Apple has today patented a new approach to how it uses memory in the System-on-Chip (SoC) subsystem. With the announcement of the M1 processor, Apple has switched away from the traditional Intel-supplied chips and transitioned into a fully custom SoC design called Apple Silicon. The new designs...

www.techpowerup.com

That patent describes various ways of how RAM topology can be organized. There is no mention how this can enable replaceable RAM. In fact, most of the diagrams depict RAM that is integrated on the package in this or other form.

I can see a scenario where the Mac Pro will come with up to 256GB of unified RAM that can be shared between the CPU, GPU, NPU. Then you can install up to an additional 1.256tb of RAM on your own. This 1.256tb can only be accessed by the CPU when the original 256GB is exhausted.

This makes very little sence to me. The CPU cluster does not have its own memory controllers, it is fed from the cache and memory controllers are shared by all processing clusters on the SoC. What would be the benefit of locking the “external” RAM to CPU use only? It would make much more sense to integrate this kind of (slow, extendable) RAM into the cache hierarchy instead, so that the memory access always goes this way:

cluster-internal cache (L1/L2)
SoC cache
* high-bandwidth RAM
* low-bandwidth high capacity RAM

* denotes memory controllers

 

[Boil]

For laptops, zero chance we will see upgradeable memory. However, there is a decent chance that Apple will allow upgradeable memory for Mac Pro.

Intel Mac Pros can go up to 1.5TB. There is no way Apple is going to solder on 1.5TB. And Apple needs to match the Intel memory capacity so Apple Silicon doesn't look inferior.

Apple has a patent on a multi-level RAM system:

Apple Patents Multi-Level Hybrid Memory Subsystem

Apple has today patented a new approach to how it uses memory in the System-on-Chip (SoC) subsystem. With the announcement of the M1 processor, Apple has switched away from the traditional Intel-supplied chips and transitioned into a fully custom SoC design called Apple Silicon. The new designs...

www.techpowerup.com

I can see a scenario where the Mac Pro will come with up to 256GB of unified RAM that can be shared between the CPU, GPU, NPU. Then you can install up to an additional 1.256tb of RAM on your own. This 1.256tb can only be accessed by the CPU when the original 256GB is exhausted.

This would work with my thoughts towards a Mac Pro Cube...

Vertically mounted 2019 Mac Pro-style double-sided mobo; SoCs (SiP/MCM/whatever) on the front of the mobo (amongst other things); replaceable RAM (and NVMe SSDs...?) on the back of the mobo... Redundant PSUs on opposite side of chassis... 2019 Mac Pro-style heat sink filling majority of remaining internal volume...

2019 Mac Pro-style 3D venting front & rear; intake on the front with a 180mm fan, exhaust out the rear...

Single PCIe Gen5 x16 half-length slot, primary use for tethering an external PCIe expansion chassis...

 

[Spindel]

I predicted almost a year ago that upgradable "RAM" might come to products like the MacPro. But it will not operate as people expect RAM to operate.

It will be used more as a fast "swap" than RAM. Basically another layer of memory will be added.


Very simplified today memory structure looks like this:

On die cache (that in it self is structured in different levels) -> RAM -> Swap (on SSD/HDD)

My prediction for a future AS Mac Pro is the following:

On die cache (that in it self is structured in different levels) -> RAM -> Fast Swap (on traditional DIMM/SODIMM) -> Swap (on SSD/HDD)


I stand by this prediction.



Sorry if anyone allready posted this kind of solution in this thread, I CBA to read all 5 pages.

 

[leman]

I predicted almost a year ago that upgradable "RAM" might come to products like the MacPro. But it will not operate as people expect RAM to operate.

It will be used more as a fast "swap" than RAM. Basically another layer of memory will be added.


Very simplified today memory structure looks like this:

On die cache (that in it self is structured in different levels) -> RAM -> Swap (on SSD/HDD)

My prediction for a future AS Mac Pro is the following:

On die cache (that in it self is structured in different levels) -> RAM -> Fast Swap (on traditional DIMM/SODIMM) -> Swap (on SSD/HDD)


I stand by this prediction.



Sorry if anyone allready posted this kind of solution in this thread, I CBA to read all 5 pages.

Well, that's the most straightforward and obvious solution to the extensibility problem. You are probably not the first and definitely not the last person to suggest it In fact, I would say this it the first solution that comes to a mind of a logical person who has some basic knowledge of how memory works.

 

[Gnattu]

That patent describes various ways of how RAM topology can be organized. There is no mention how this can enable replaceable RAM. In fact, most of the diagrams depict RAM that is integrated on the package in this or other form.

The very first diagram shows that the 2nd tier is off-package though. It is on the "motherboard". Some of the integration looks crazy to me like the below one, how could they cool this thing?

 

[dogslobber]

@dogslobber What's the point of quoting responses to your posts without any further comment or answer? ?

I always re-quote naive/silly quotes incase the authors decide to delete them.

 

[Timpetus]

For that special project you could enable as much ram as is available in your computer with a push of a button. Once complete you drop down to your "baseline allocation" of ram for the everyday stuff. This would allow corporations to buy baseline computers knowing they'll be more than sufficient the majority of the time and then as special occasions present themselves that require a more powerful computer they rent as much Ram as necessary. It might not just be ram that they're renting, it could also be gpu cores as well.

Still makes no sense at all to do this with hardware that costs a significant % of the overall BoM. This model only makes sense for hardware that is either made cheaper overall by reducing variants in manufacturing or for remote hardware that you're accessing when needed, like VMs in a data center or remote game streaming services like GeForce Go.

 

[dogslobber]

Still makes no sense at all to do this with hardware that costs a significant % of the overall BoM. This model only makes sense for hardware that is either made cheaper overall by reducing variants in manufacturing or for remote hardware that you're accessing when needed, like VMs in a data center or remote game streaming services like GeForce Go.

Boom. You can always tell folk who don't work in this industry from the lack of understanding and grasping for old thinking. As Steve said, skate to where the puck is going, not where it currently is.

 

[Timpetus]

Boom. You can always tell folk who don't work in this industry from the lack of understanding and grasping for old thinking. As Steve said, skate to where the puck is going, not where it currently is.

Seems you don't understand any industry. The future of business isn't wasting money, unless you're in the public sector...

 

[Analog Kid]

Boom. You can always tell folk who don't work in this industry from the lack of understanding and grasping for old thinking. As Steve said, skate to where the puck is going, not where it currently is.

You can also tell people who don’t understand a business model because their reason for following it is because it’s “how industry is going” rather than because of how it applies to the case at hand.

As a sports metaphor, that’s like 5 year olds playing soccer where it’s just a cluster of kids moving in a swarm around the field. Sometimes it makes more sense to not go where everyone else is and to position one’s self in a location better suited to the overall strategy.

 

[Analog Kid]

The very first diagram shows that the 2nd tier is off-package though. It is on the "motherboard". Some of the integration looks crazy to me like the below one, how could they cool this thing?

View attachment 1917874

Anyone have the patent number on this? I don’t see it on the site linked…

 

[Gnattu]

Anyone have the patent number on this? I don’t see it on the site linked…

US10573368B2

 

[ThomasJL]

I'm expecting that Apple will allow user to upgrade the unified memory in future ARM Macs. This will also likely make it cheaper to manufacture as it will reduce the parts needed to make Macs. This means if you buy a bottom of the line Mac then there will be headroom to grow the unified memory footprint easily. Feels like Apple will be onto a winner with it.

Your post suggests that Tim Cook cares mostly about users and cares about the environment. He doesn’t. He cares mostly about shareholders. For that reason, it’s not likely that there will be user-upgradable RAM in ARM Macs, just as there hasn’t been user-upgradable RAM in the Intel MacBook line starting in 2012.

 

[leman]

Your post suggests that Tim Cook cares mostly about users and cares about the environment. He doesn’t. He cares mostly about shareholders. For that reason, it’s not likely that there will be user-upgradable RAM in ARM Macs, just as there hasn’t been user-upgradable RAM in the Intel MacBook line starting in 2012.

I find the claims that upgradeability is better for the environment or interesting to the users to be highly dubious. Can you offer an example how user-upgradeable high-bandwidth RAM would lead to a more environmentally-friendly implementation? It would require significantly higher investment of materials, larger chassis and would consume more power.

 

[mr_roboto]

I'm expecting that Apple will allow user to upgrade the unified memory in future ARM Macs. This will also likely make it cheaper to manufacture as it will reduce the parts needed to make Macs. This means if you buy a bottom of the line Mac then there will be headroom to grow the unified memory footprint easily. Feels like Apple will be onto a winner with it.

No, you folks are thinking about it the old way. This hardware industry is moving to a licensing model where HW vendors ship one single entity which has hardware licenses to enable additional hardware features. In effect, Apple will always ship maximum configs but you'll only be licensed to use the version you bought. You can buy additional hardware licenses to enable more cores, more memory, more storage.

Laughing so hard at "reduce the parts needed to make Macs". If every machine is the maximum config, Apple's going to be buying a lot more DRAM.

The licensing model you mention isn't something the hardware industry is moving to, it's something which has been around for a long time. It's mostly stayed in the realm of big-iron IBM hardware, where:

• the price of the base machine is so high that they can easily afford to build some disabled upgrades in and still make a huge margin
• volumes are very low
• IBM makes tons of money on what amount to very high price subscription services, which most big-iron customers buy. Being able to depend on selling high margin services for years makes it more attractive to get less profit from the initial hardware sale.
• IBM can reasonably expect that a large fraction of customers buying small configs will eventually want to pay for a soft-upgrade. Big computers tend to be run for a decade or more and the load often grows over time. (Think databases, for example - DBs usually grow.)
• A lot of the customers really care about trying to achieve five-nines system uptime, or they wouldn't be buying super expensive IBM hardware and services. Removing the need for a hardware upgrade to involve actually touching hardware has value to them.

Only one of these applies to Apple (services income), and you have to ignore the fundamental differences between the kind and profitability and adoption levels of the services each company offers.

The items which don't apply are pretty deadly to your idea. Apple probably sells multiple million base model MacBook Airs every year. Paying for every one of those to have fully unlockable 16GB and 8-core GPU would not be pleasant, because they can count on the vast majority of those customers never wanting an upgrade - the average buyer of a base Air is never going to use much beyond a web browser and a few office productivity apps.

 

[adib]

I'm not convinced that Apple will support user-replaceable RAM again, even on the Mac Pro.

I expect the large iMac will offer single or double M1 Pro / Max SoCs, with up to 128GB RAM

The Mac Pro may offer 4 x M1 Max at up to 256GB, with a possibility of doubling the RAM modules capacity at the some point to give 512GB.

If they did offer additional memory, I think they would need to extend the Apple Silicon architecture to support "local" and "extended" RAM, which would probably need a new version of MacOS to support tiered memory (similar to tiered storage)

User-replacable SoC, on the other hand, could be possible. On a hypothetical Mac Pro, the Mx+Memory chip could be housed in a user-replaceable board along with other PCIe cards. Thus users can upgrade the Mx SoC but keep their RAID controllers, etc the same. Maybe have a dual or triple Mx SoC options.

 

[Zdigital2015]

Your post suggests that Tim Cook cares mostly about users and cares about the environment. He doesn’t. He cares mostly about shareholders. For that reason, it’s not likely that there will be user-upgradable RAM in ARM Macs, just as there hasn’t been user-upgradable RAM in the Intel MacBook line starting in 2012.

The trend began in 2008 with the introduction of the MacBook Air.

 

[ThomasJL]

The trend began in 2008 with the introduction of the MacBook Air.

You’re right about that. I should have written “MacBook Pro line starting in 2012” instead of “MacBook line starting in 2012.”

 

[shimy1984]

The all-in-one SOC is Apple’s way of skirting the right to repair issue (with the added benefit of being faster for the consumer).

If you want to repair/upgrade the CPU or GPU, guess what?.. you’re gonna be paying Apple for a new chipset.

You want more RAM? Guess what?.. you’re gonna be paying Apple for a new chipset.

This all ties into Apple opening up the capability for users to upgrade components again… the only reason they are is they found a way to be the only vendor that could be paid for the repairs.

With that said, I could see a RAM expansion that would essentially be used as a replacement for swap memory. So, you could have 16gb on the chip, 16 gb expanded, then anything that falls through goes to swap.

Just my two cents but seems pretty logical to me.

 

[leman]

The all-in-one SOC is Apple’s way of skirting the right to repair issue (with the added benefit of being faster for the consumer).

Yeah, in similar way how flight companies skirt the right to walk issue... you either walk or fly, can't have both at the same time.

Apple doesn't do it to prevent the customers from doing their own upgrades. Apple does it because it is the only reasonable technical way to achieve what they want to do. The very concept of their hardware (performance, energy efficiency, form factor) relies on tight integration and tight integration means non-modular, non-replaceable components.