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LPCAMM2 is a modular, repairable, upgradeable memory standard for laptops

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Re: LPCAMM2 is a modular, repairable, upgradeable memory standard for laptops

#111

Post by klausa »

tombert wrote: post #67
orev wrote: post #14

I’m glad they explained why RAM has become soldered to the board recently. It’s easy to be cynical and assume they were doing it for profit motive purposes (which might be a nice side effect), but it’s good to know that there’s also a technical reason to solder it. Even better to know that it’s been recognized and a solution is being worked on.

Yeah, I was actually surprised to learn there was a reason other than "Apple wants you to buy a new Macbook or overspec your current one". It's annoying, but at least there's a plausible reason to why they do it.

Apple's RAM is not soldered to the _motherboard_, it's part of the SoC package.

Re: LPCAMM2 is a modular, repairable, upgradeable memory standard for laptops

#113

Post by jwells89 »

teaearlgraycold wrote: post #92
7speter wrote: post #77

Earlier quoted context omitted.

Apple could just make lower tier macbooks but mac fanboys wouldnt be able to ask “but what about apples quarterly profits?” Most macbooks dont need high memory bandwidth, most users are using their macs for word processing, excel and vscode.

Yes but Apple’s trying to build an ecosystem where users get highly quality, offline, low latency AI computed on their device. Today there’s not much of that. And I don’t think they even really know what’s going to justify all of that silicon in the neural engine and the memory bandwidth. Imagine 5 years from now people have built whole stacks on that foundation. And then competing laptops need to ship that compute t…

Apple is also deliberately avoiding having “celeron” type products in their lineup because those ultimately mar the brand’s image due to being kinda crap, even if they’re technically adequate for the tasks they’re used for.

They instead position midrange products from 1-2 gens ago as their entry level which isn’t quite as cheap but is usually also much more pleasant to use than the usual bargain basement stuff.

Re: LPCAMM2 is a modular, repairable, upgradeable memory standard for laptops

#114

Post by enragedcacti »

j16sdiz wrote: post #108
baby_souffle wrote: post #4

This is fantastic news. Hopefully the cost to manufacturers is only marginal and they find a suitable replacement for their current "each tier in RAM comes with a 5-20% price bump" pricing scheme. Too bad apple is almost guaranteed to not adopt the standard. I miss being able to upgrade the ram in macbooks.

Unified memory is basically L3 cache speed with zero copy between CPU and GPU. They have engineering difference. Depends on who you ask, it may or may not worth it

Assuming you mean latency, Apple's unified memory isn't lower latency than other soldered or socketed solutions e.g. M1 Max with 111ns latency on cache miss vs 13900k with 93ns latency. Certainly not L3 level latency. Zero copy between CPU/GPU is great but not unique to unified memory or soldered ram.

As far as bandwidth goes, you would only need one or two LPCAMM2 modules to match or exceed the bandwidth of non-Max M series chips. Accommodating Max chips in a macbook with LPCAMM2 would definitely be a difficult packaging problem.

https://www.anandtech.com/show/17024/apple-m1-max-performanc...

https://www.anandtech.com/show/17047/the-intel-12th-gen-core...

Re: LPCAMM2 is a modular, repairable, upgradeable memory standard for laptops

#115

Post by jwells89 »

seanp2k2 wrote: post #99
jauntywundrkind wrote: post #25

Earlier quoted context omitted.

Hoping we see AMD Strix Halo with it's 256-bit interface crammed into an aggressively cooled fairly-thin fairly-light. But it's going to require heavy cooling to make full use of. Heck, make it only run full tilt when on an active cooling dock. Let it run half power when unassisted.

Kinda hilarious to see gamers buying laptops that can't actually leave the house in any practical meaningful way. I feel like some of them would be better off with SFF PCs and the external monitors they already use. I guess the biggest appeal I've seen is the ability to fold up the gaming laptop and put the dock away to get it off the desk, but then moving to an SFF on the ground plus a wireless gaming keyboard and w…

I’ve been wondering for a while now why ASUS or some other gaming laptop manufacturer doesn’t take one of their flagship gaming laptop motherboards, put some beefy but quiet cooling on it, put it in a pizza-box/console enclosure, and sell it as a silent compact gaming desktop.

A machine like that could still be relatively small but still be dramatically better cooled than even the thickest laptop due to not having to make space for a battery, keyboard, etc.

Re: LPCAMM2 is a modular, repairable, upgradeable memory standard for laptops

#116

Post by Dylan16807 »

nwah1 wrote: post #33
farmdve wrote: post #18

Earlier quoted context omitted.

These are very obscure, or perhaps I mean to say niche laptop manufacturers. We need this standard for all of them, HP, Lenovo, Acer etc.

Framework open sources most of their schematics, if I understand correctly. So it should be possible for others to use the same standard, if they wanted to. (they don't want to)

The form factor isn't great for being a vendor-neutral thing.

If we can convince the companies to actually try for compatibility, then a revival of MXM is probably a significantly better option.

Re: LPCAMM2 is a modular, repairable, upgradeable memory standard for laptops

#117

Post by Dylan16807 »

0x457 wrote: post #48
ThinkBeat wrote: post #23

Meanwhile Apple bakes the RAM,CPU,GPU all into the same "chip". Good luck with that.

Meanwhile, Apple ships machines with a 1024bit wide memory bus, while this solution offers just 128 bits per "stick".

Compared to how big the CPU package is on those machines, 4 of these sticks on each side of the motherboard should fit acceptably.

And you'd be able to have a lot more than 192GB.

Re: LPCAMM2 is a modular, repairable, upgradeable memory standard for laptops

#118

Post by magicalhippo »

kjkjadksj wrote: post #75
magicalhippo wrote: post #39

Earlier quoted context omitted.

The physical size of the socket and having the connections on the edge means you're forced to have much longer traces. Longer traces means slower signalling and more power loss due to higher resistance and parasitics. This[1] Anandtech article from last year has a better look at how the LPCAMM module works. Especially note how the connectors are now densely packed directly under the memory chips, significantly reduci…

I'd wager for most consumers capacity is more important than bandwidth and the power losses are going to be small compared to the rest of the stack.

> power losses are going to be small compared to the rest of the stack

While certainly not the largest losses, they do not appear insignificant. In LPDDDR4 they introduced[1] a new low-voltage signalling, which I doubt they could have gotten working with SODIMMs due to the extra parasitics.

If you look at this[2] presentation you can see that at 3200MHz a DDR4 SODIMM would consume around 2 x 16 x 4 x 6.5mW x 3.2GHz = 2.6W for signalling going full tilt. Thanks to the new signalling LPDDR4 reduces this by 40% to around 1.6W.

Compare that to a low-power CPU having a TDP of 10W or less a full 1W reduction per SODIMM just due to signalling isn't insignificant.

To further put it into perspective, the recent Lenovo ThinkPad X1[3] uses around 4.15W average during normal usage, and that includes the screen.

Obviously the memory isn't going full tilt at normal load, but say average 0.25W x 2 sticks would reduce the X1's battery lifetime by 10%.

edit: yes I'm aware the presentation is about LPDDR4 yet the X1 uses LPDDR5, just trying add context using available sources.

[1]: https://www.jedec.org/news/pressreleases/jedec-releases-lpdd...

[2]: https://www.jedec.org/sites/default/files/JY_Choi_Mobile_For...

[3]: https://www.tomshardware.com/reviews/lenovo-thinkpad-x1-carb...

Re: LPCAMM2 is a modular, repairable, upgradeable memory standard for laptops

#119

Post by antonkochubey »

jwells89 wrote: post #115
seanp2k2 wrote: post #99

Earlier quoted context omitted.

Kinda hilarious to see gamers buying laptops that can't actually leave the house in any practical meaningful way. I feel like some of them would be better off with SFF PCs and the external monitors they already use. I guess the biggest appeal I've seen is the ability to fold up the gaming laptop and put the dock away to get it off the desk, but then moving to an SFF on the ground plus a wireless gaming keyboard and w…

I’ve been wondering for a while now why ASUS or some other gaming laptop manufacturer doesn’t take one of their flagship gaming laptop motherboards, put some beefy but quiet cooling on it, put it in a pizza-box/console enclosure, and sell it as a silent compact gaming desktop. A machine like that could still be relatively small but still be dramatically better cooled than even the thickest laptop due to not having to…

ZOTAC does these - there are ZBOX Magnus with laptop-grade RTX 4000 series GPUs in 2-3 liter chassis. However their performance and acoustics are rather.. compromised, compared to a proper SFF desktop (which can be built in ~3x the volume)

Re: LPCAMM2 is a modular, repairable, upgradeable memory standard for laptops

#120

Post by sliken »

7speter wrote: post #77
pja wrote: post #22

Earlier quoted context omitted.

This PDF[1] suggests that an LPCAMM2 module has a 128 bit wide memory interface, so the epic memory bandwidth of the M3 max won’t be achievable with one of these memory modules. High end devices could potentially have two or more of them arranged around the CPU though? [1] https://investors.micron.com/node/47186/pdf

Apple could just make lower tier macbooks but mac fanboys wouldnt be able to ask “but what about apples quarterly profits?” Most macbooks dont need high memory bandwidth, most users are using their macs for word processing, excel and vscode.

Even low end gaming, simulations, and even fun webGL toys can require a fair amount of memory bandwidth with an iGPU, like apple's M series. It also helps quite a bit for inference. I MBP with a M3 max can run models requiring multiple GPUs on a desktop and still get decent perf for single users.
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