And conveniently, by making your machine non upgradeable, it allows the manufacturer to enforce market segmentation / charge a huge premium for small RAM upgrade (a la Apple)
LPCAMM2/SOCAMM2 exist, heck I think Framework is using LPCAMM2 in one of their new laptops.
Heck, I'm willing to bet that a lot of manufacturers would rather go that route than soldered in, if for no other reason than the relative cost of warranty work between the two.
However, people probably need to stop being obsessed with ultrathin laptops for that to happen.
> However, people probably need to stop being obsessed with ultrathin laptops for that to happen.
I've never been able to understand this. Once we made it down to ~20 mm (which for the record still accommodates dual-stacked SO-DIMMs, a 2.5 inch bay, and a user replaceable battery but not an RJ45 jack) I don't understand what the practical impact of any further reduction is supposed to be. Regardless of how thin you make it the thing will still be a massive rectangle that you can't flex or press on.
> Regardless of how thin you make it the thing will still be a massive rectangle that you can't flex or press on.
There's very wide variation between laptops in how noticeably they'll flex or yield or creak when pressed. Laptops with a build quality that actually feels solid are far from being ubiquitous or even a majority.
Doubling the thickness of my MacBook Air would probably make it regress on that solid feeling, unless the weight was also significantly increased.
And regardless of whether current laptop form factors could accommodate a 2.5" drive, there's no use in doing so. That drive form factor is entirely obsolete for laptops and is just a waste of space and materials, and has been for about a decade.
I wasn't saying that I want a 2.5 inch drive, I was merely listing off a number of rather large things that fit just fine within a 20 mm budget.
I'm not sure why you seem to think that making something thicker would reduce the stiffness or strength. It's generally the opposite - see the concept of a torsion box. Anyway that wasn't the point. The point was that regardless of how thin you make the thing it will forever remain a cumbersome and delicate item that you have to treat with care when packing so what meaningful positive impact does shaving off those last few mm have? It's never made any sense to me.
I came here to say just this myself! Modern DIMM formats make SFF/portable builds with unified memory pools far more plausible than prior designs. There's absolutely no reason desktop machines couldn't implement similar DIMM formats or design a new board standard around something similar.
Unified memory doesn't have to be soldered on or serviceable. That's a choice Apple made because it fit their product vision, but it's not mandatory in the slightest.
LPCAMM2 is available in real systems at 7467MT/s and 120ns latency, vs apple (and intel) at 9600MT/s (and apple soldered memory at 100ns latency).
I don't know how linear or sensitive CPU and GPU benchmarks are to such a 20% slowdown, but i don't think Apple wants to pay it. And it looks like the next generation will be even closer to the SOC.
how about the LPCAMM route? Framework uses LPCAMM2 in 13 Pro laptop mainboards and claims that it satisfies the iGPU and NPU hardware without needing soldered RAM
Thought getting sleep right was something that happened before MS decided they need to be able to wake your PC any time they want and not hardware related much.
A note that this was rather common on the days before PC clones took off.
The vertical integration many associate with Apple, was the common approach to most 8 and 16 bit home computers.
Naturally after all these years, many PC vendors want their margins back, and thus the phenomenon of everyone going back to vertical integration, especially in form factors that are ideal for such, like laptops, tablets and phones.
So the option boils down to classical desktops, or being picky on which laptops to buy.
I mean is it possible to make unified memory systems with good performance or is it not really feasible due to memory timing/trace length issues?
It’s possible if you’re willing to go with much slower RAM than GPUs like but CPUs often use. Thats what integrated graphics laptops have done for a long time right?
But can you get high end CPU and GPU performance with unified memory and maintain user upgradable memory in a reasonable way? Thats what I don’t know.
> I mean is it possible to make unified memory systems with good performance or is it not really feasible due to memory timing/trace length issues?
LPCAMM and similar solutions exist, but have never been demonstrated running at speeds that match what the leading soldered memory systems are using; there's always been some speed penalty. I'm not sure we've ever seen a system demonstrated using LPCAMM or similar for a 512-bit bus to match Apple's Max tier SoCs, so it's somewhat of an open question whether those solutions can offer upgradability at the high end of the market for unified memory systems.
> LPCAMM and similar solutions exist, but have never been demonstrated running at speeds that match what the leading soldered memory systems are using; there's always been some speed penalty.
LPCAMM2 supports up to 9600MT/s, which appears to be the same speed Apple is using.
> I'm not sure we've ever seen a system demonstrated using LPCAMM or similar for a 512-bit bus
Servers commonly use a 768-bit DDR5 memory bus per socket even without LPCAMM and LPCAMM allows shorter traces than traditional DIMMs. It's basically down to most existing DDR5 system boards/sockets having been designed before anyone was trying to run LLMs on consumer hardware, e.g. AM5 has a 128-bit memory bus and you're not changing that without a new socket. But every memory generation gets a new socket anyway, and the existing Threadripper Pro socket has a 512-bit memory bus as well.
Moreover, making the bus wider is "easy" -- the main problem with it is that it adds cost. Apple's least expensive machines use the same 128-bit memory bus as most PCs and the ones with the 512-bit bus cost as much as Threadripper if not more.
> LPCAMM2 supports up to 9600MT/s, which appears to be the same speed Apple is using.
The difference here is in what the standard defines on paper vs what is actually shipping in products and readily available off the shelf. Who's selling a whole system with LPCAMM2 certified for 9600MT/s? Intel's current-gen Panther Lake top of the line laptop chips are rated for 9600MT/s when using soldered LPDDR5x but only 7467MT/s when using LPCAMM2, according to their current datasheet: https://www.intel.com/content/www/us/en/content-details/8721...
That puts the current Intel-with-LPCAMM2 supported memory speed at 1.5 years and counting lag behind Apple's shipping memory speeds. Intel's own shipping memory speed moved past 7467MT/s a few months earlier than even Apple's.
> Servers commonly use a 768-bit DDR5 memory bus per socket even without LPCAMM and LPCAMM allows shorter traces than traditional DIMMs.
> Moreover, making the bus wider is "easy"
Citations needed. Servers aren't anywhere close to 9600MT/s yet; Intel and AMD are at 6400MT/s. The trace length advantages offered by LPCAMM2 don't necessarily mean the traces for the sixth or eighth channel would be short enough for 9600MT/s (which again, is not yet available even in a 128-bit configuration in shipping hardware). Adding more channels to even a LPCAMM2 configuration means adding more trace length, because only two modules can actually be adjacent to the CPU socket. (Maybe you could get to 512-bit with modules on the front and back of the board while maintaining trace lengths short enough to reach meaningfully higher speeds than regular DDR5, but so far nobody is doing that or even talking about it.)
> LPCAMM and similar solutions exist, but have never been demonstrated running at speeds that match what the leading soldered memory systems are using;
Does it need to be leading, though? Being median is just fine for what high-RAM systems are intended to be used for.
Don't I/you wish. The mechanical junction adds no delay, only manufacturing expense, and the delay of purchasing new systems to keep up with OS bloat.
Actually the opposite is true. Socketed RAM can be made to overclock and adjust timings, while soldered ram, no. Two Lenovo's one soldered ( Carbon X1 ), one T590, one slot: Crucial 16GB, 260-pin SODIMM, DDR4 PC4-19200. Exact same processor, the X1 is DDR3 soldered on 532.0 MHz PC3-1066. The T590, has DDR4, PC4-19200, 1200Mhz.
Both have a Core i7 8665U... and the T590 is much faster, with socketed ram.
I think you'll find that in the current day, high speed LP(?)DDR5 requires a better signal path than what the SODIMM can provide. Which is why laptop makers initially moved to soldered RAM before moving to CAMM (probably only for the high end ones).
Maybe I won't care about upgradeability right now. The architecture is clearly in flux, the roles of traditional "CPU" and "GPU" are rapidly evolving. Maybe in 5 years, or even 3 years, a brand-new machine from 2026 won't be worth upgrading for a new role due to a seriously different architecture, but would only be relegated to do something "traditional".
I wish manufacturers could consider a hybrid approach. There should be no reason an architecture can't support both unified memory (effectively L4(?) cache), and cheaper, upgradeable system memory on sticks for old-school application use.
Upgradable memory and unified memory aren't entirely mutually exclusive. You can design a chip that uses DDR5 and has a decently-powerful iGPU that can use that whole memory pool. But you'll be starving that GPU of bandwidth relative to what you'd achieve with soldered LPDDR, and it's not really worth the trouble of building a large iGPU unless you're also going to feed it with the fastest memory you can reasonably put down.
If you look at eg. an Intel laptop chip, you'll see they design and build a memory PHY that can interface with either DDR5 or LPDDR5x. They don't support splitting it to have one controller operating with DDR5 and the other with LPDDR5x, for fairly obvious reasons: more complex hardware, harder for software/operating systems to manage optimally, and not a lot of benefits to drive demand and justify the expenses. The speed difference between LPDDR5x and DDR5 isn't really large enough to use LPDDR5x as an L4 cache; it would be more like two different NUMA nodes, with complications for laptop power management.
If you want somebody to build a chip with more than the usual 128-bit bus and make some of the memory controllers use LPDDR and some DDR5, then you're asking for a significant increase in chip cost due to the extra memory PHYs and pin count. That cost is only justified if almost all products using the bigger chips are going to actually take advantage of the full complement of memory controllers.
AFAIK PCIe6 just started getting implemented in hardware last year... PCIe7 Spec was just released last year too...
PCIe6 is a much larger change than 'just bump up the transfer rate', the encoding changed too (on top of the new code length, it's no longer NRZ,) so everyone needed to design and validate both the new encoding block, negotiation, etc etc.
That said, I'm guessing PCIe7 will be a 'smoother' transition from PCIE6, i.e. we might see 7.0 products in 2027. That will theoretically get you ~240GB/sec, on an x16 link, or hypothetically a little less than the hypothetical max of a current Strix Halo. (I'm guessing however, that PCIe protocol overhead will make the difference larger.)
LPCAMM2/SOCAMM2 exist, heck I think Framework is using LPCAMM2 in one of their new laptops.
Heck, I'm willing to bet that a lot of manufacturers would rather go that route than soldered in, if for no other reason than the relative cost of warranty work between the two.
However, people probably need to stop being obsessed with ultrathin laptops for that to happen.