CAMM = Compression Attached Memory Module
CAMM to Usurp SO-DIMM Laptop Memory Form Factor Says JEDEC Member
So, farewell, SO-DIMM. After a quarter century of service in laptop, all-in-ones and other compact designs, it looks like the end of the road for SO-DIMM is in sight. JEDEC committee member and Dell Senior Distinguished Engineer, Tom Schnell, told PC World that the new 'CAMM Common Spec' will be the next RAM standard for laptops. There already seems to have been a lot of progress in the background, with the v0.5 spec already approved by 20 or so companies in the task group, and JEDEC expected to finalize the v1.0 spec in the second half of this year.
[...] The new information from PC World editor Gordon Ung's chat with Tom Schnell helps us weigh up some of the pros and cons of CAMM, and point to some ways it has progressed from Dell's pre-JEDEC-approved spec. Apparently, as well as improved density (more RAM capacity in a smaller space), CAMM is amenable to "scaling to ever higher clock speeds." Specifically, the new information indicates that the DDR5-6400 'brick wall' for SO-DIMMs will be shrugged off by CAMMs.
When CAMM reaches devices, there are a couple of tech advances which could help spur its adoption. We mentioned the faster DDR5 speeds above, but it is thought that CAMM could really take off when DDR6 arrives. Another appealing variation might be for adding LPDDR(6) memory to laptops. Traditionally LPDDR memory is soldered, so the new spring contact fitting modules might mean much better upgradability for the thinnest and lightest devices which tend to use LPDDR memory.
Previously: Dell Defends its Controversial New Laptop Memory (CAMM)
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Dell defends its controversial new laptop memory
If you were triggered over word that Dell is pushing a proprietary memory standard, take a chill pill. Dell's new memory design isn't really proprietary and may actually lead to benefits for performance laptops.
The controversy kicked up last week when images of Dell's new CAMM, or Compression Attached Memory Module, leaked out. This immediately lead tech sites to declare that Dell was taking a path to "lock out user upgrades" and warning laptop users who like to upgrade their memory that they were "out of luck."
In an interview with PCWorld, however, both the person who designed and patented the CAMM standard, as well as the product manager of the first Dell Precision laptop to feature it, assured us the intent of the new memory module standard is to head-off looming bandwidth ceilings in the current SO-DIMM designs. Dell's CAMM, in fact, could increase performance, improve reliability, aid user upgrades, and eventually lower costs too, they said.
[...] [Dell's Tom] Schnell said that Dell isn't making the modules and has worked with memory companies as well as Intel on this. In the future, a person with a CAMM-equipped laptop will be able to buy RAM from any third party and install it in the laptop. Yes, initially, Dell will likely be the only place to get CAMM upgrades, but that should change as the standard scales up and is adopted by other PC makers. The new memory modules are also built using commodity DRAMs just like conventional SO-DIMMs.
[...] So why do we need CAMM anyway? Dell's Schnell said that SO-DIMM, or Small Outline Dual Inline Memory Module, is headed for a glass ceiling within a generation of design. SO-DIMMs, which were first introduced almost 25 years ago, haven't changed much in all that time besides moving to newer and faster DRAM methods.
The CAMM2 spec was recently finalized, and memory makers are testing the waters:
Of all the PC-related things to come out of CES this year, my favorite wasn't Nvidia's graphics cards or AMD's newest Ryzens or Intel's iterative processor refreshes or any one of the oddball PC concept designs or anything to do with the mad dash to cram generative AI into everything.
No, of all things, the thing that I liked the most was this Crucial-branded memory module spotted by Tom's Hardware. If it looks a little strange to you, it's because it uses the Compression Attached Memory Module (CAMM) standard—rather than being a standard stick of RAM that you insert into a slot on your motherboard, it lies flat against the board where metal contacts on the board and the CAMM module can make contact with one another.
CAMM memory has been on my radar for a while, since it first cropped up in a handful of Dell laptops. Mistakenly identified at the time as a proprietary type of RAM that would give Dell an excuse to charge more for it, Dell has been pushing for the standardization of CAMM modules for a couple of years now, and JEDEC (the organization that handles all current computer memory standards) formally finalized the spec last month.
[...] It used to be easy to save some money on a new PC by buying a version without much RAM and performing an upgrade yourself, using third-party RAM sticks that cost a fraction of what manufacturers would charge. But most laptops no longer afford you the luxury.
Most PC makers and laptop PC buyers made an unspoken bargain in the early- to mid-2010s, around when the MacBook Air and the Ultrabook stopped being special thin-and-light outliers and became the standard template for the mainstream laptop: We would jettison nearly any port or internal component in the interest of making a laptop that was thinner, sleeker, and lighter.
[...] The CAMM standard (technically finalized as CAMM2) tries to offer the best of all possible worlds.
(Score: 3, Interesting) by turgid on Wednesday January 18 2023, @10:16PM (3 children)
What sort of compression? Does it to entropy encoding on the data? That will end it tears.
I refuse to engage in a battle of wits with an unarmed opponent [wikipedia.org].
(Score: 4, Interesting) by RS3 on Thursday January 19 2023, @12:26AM (1 child)
You remember seeing the old clothes washing machines with the two compression rollers?
But seriously, it's not data compression, but rather mechanical connector compression, much like CPUs that have the flat bottom with pads, rather than pins. The "socket" (if you can call it that) has little flexible and springy fingers that contact the underside of the module.
I was trying to figure out what problem this solves. Gleaning from various this and that articles, it seems to increase connector density, which helps shorten the wire paths between RAM and CPU. (Shorter paths means faster possible speeds).
Also from looking at the diagrams, DIMM and SODIMM connectors have a "U" shaped connector, which makes parallel contact with both sides of the module. That's electrically bad in that it creates two different length but parallel paths for the signal, which means signal pulses moving through the longer path will meet up with and add to the same pulse that moved through the shorter path, but slightly later, therefore widening the electrical pulses. Wider pulses means lower maximum frequency, or more data errors if you try to push the frequency.
The CAMM socket has only one path, so the pulses stay narrower and cleaner, which means faster speeds are possible.
(Score: 4, Informative) by RS3 on Thursday January 19 2023, @12:29AM
I meant to link to this pic which helps visualize the parallel versus single paths:
https://cdn.mos.cms.futurecdn.net/5htHVduZiMb7hL3w2UBBu7-1200-80.jpg.webp [futurecdn.net]
(Score: 4, Insightful) by bzipitidoo on Thursday January 19 2023, @12:01PM
This, this is why "data compression" is bad terminology. Totally misrepresents what is really going on, giving the impression that storage needs are being reduced by somehow increasing the density of the data. Entropy, not density, is what's being increased. I say it should be called "redundancy removal", or "redundancy reduction". Could also try "irrelevancy removal" for what we currently call "lossy compression".
(Score: 2) by driverless on Thursday January 19 2023, @02:56AM (6 children)
It's amazing how both this site and the Other Site all managed to go on an on about CAMM without ever telling us WTF CAMM actually is (beyond some new gee-whiz magical memory). Even TFA only mentions it in the byline with no information on what it is that makes it better.
(Score: 1, Touché) by Anonymous Coward on Thursday January 19 2023, @04:11AM
You must be new here.
(Score: 3, Informative) by RS3 on Thursday January 19 2023, @08:01AM
I find many things that way- people talk about a thing, without ever telling you what it is. Major company websites are like that- they'll talk features, options, whatever, but not the very basic: what is it?
CAMM [wikipedia.org] is a new RAM (memory) module form factor, meant to replace the DIMM and SODIMM [wikipedia.org] form factors.
It has advantages over SODIMM, mainly it will support higher capacity and faster speeds.
(Score: 4, Informative) by takyon on Thursday January 19 2023, @09:17AM
All the information you need is in the summary, and there's a previous article too.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by janrinok on Thursday January 19 2023, @09:56AM (2 children)
From the "Previously" link:
No, I don't suppose that takyon knows what colour the circuit board will be or what shape of box it might be purchased in, otherwise that information might have been included in the summary. But I think that he has done a pretty good job of providing the information that most people want to know. Of course, if you still have questions then I am sure that your favourite search engine will be able to help.
(Score: 2) by driverless on Thursday January 19 2023, @10:09AM (1 child)
Apart from the "spring contact fitting modules" the quoted text could apply to pretty much any memory technology that isn't a SO-DIMM. It's generic enough that it can be applied to almost any other new RAM tech.
(Score: 2) by Immerman on Thursday January 19 2023, @03:39PM
Is anything else actually different?
It's a new form factor, not a new memory technology.
(Score: 1) by shrewdsheep on Thursday January 19 2023, @09:51AM (3 children)
I don't get how capacity is improved. How does the package imply anything about the RAM chips? Or is it that they physical address space is expanded?
(Score: 3, Interesting) by takyon on Thursday January 19 2023, @01:37PM
Hard to say.
https://b2c-contenthub.com/wp-content/uploads/2022/04/cDIMMs_Many.jpg?resize=1200%2C783&quality=50&strip=all [b2c-contenthub.com]
It looks like they have the equivalent of 4x SO-DIMMs in the largest CAMM.
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 3, Interesting) by Immerman on Thursday January 19 2023, @04:15PM (1 child)
I think the capacity ceiling basically comes down to how many memory chips can fit in a given area (and volume). SO-DIMM only has room (and connectors) for a single row of chips per side on a stick of RAM (2 with some smaller chips), so getting a comparable number of memory chips requires at *least* 2 sticks of RAM, 2 socket connectors, and a whole lot of space either vertically or horizontally.
Combine that with the fact that SO-DIMM required clearance dimensions were established 20+ years ago when manufacturing scales were considerably larger... and there's just a whole lot of wasted space (both airspace and board-space) that makes soldered-on RAM much more attractive for compact devices.
CAMM replaces that with a single large plate where the RAM chips can be packed in as densely as the wiring allows, while requiring less than half the height clearance of a single SO-DIMM socket.
If I counted right, it also looks like CAMM has 660 pins compared to the 200 to 262 pins of DDR SO-DIMM (depending on generation). Which probably means both a few more address lines (every additional line doubles the size of the address space), and that even at the same signalling speed data can be transferred almost three times as fast as to a single SO-DIMM stick.
Fun fact - I've also heard that there's going to be different sizes of CAMM modules. e.g. a 128GB module is going to require a much larger circuit board than a 32GB module, and won't be compatible with e.g. a laptop that only has room for the smaller modules. At least until the technology miniaturizes enough to squeeze 128GB onto the smaller board size.
(Score: 3, Interesting) by takyon on Thursday January 19 2023, @04:55PM
My comment above has an image of several sizes.
It could be similar to M.2 SSDs. M.2 2280 (22mm x 80mm) is common in today's desktops, but the Steam Deck can only take an M.2 2242. I believe the Steam Deck breathed new life into that option with some new, tiny 1 TB models being announced. Then you have 25110 coming:
https://soylentnews.org/comments.pl?cid=1275741&sid=51872 [soylentnews.org]
[SIG] 10/28/2017: Soylent Upgrade v14 [soylentnews.org]
(Score: 2) by bzipitidoo on Friday January 20 2023, @04:25AM
I have always found it baffling that transistors are packed as tightly as possible on chips, and then, positioned on a circuit board so that the travel distance between chips is many orders of magnitude greater than within. I get that it helps dissipate heat, and reduces the defect rate by keeping down the number of transistors on a die, but seems the circuit board has been some seriously low hanging fruit for improvements for a good while now. Perhaps System on a Chip is the answer?