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Comment by senectus1 | Hacker News Reader

My current laptop (Dell Precision 7670) had flashing light error on the other day, that the Dell support paper suggested was potentially "loose ram".

So I turned it upside down and opened it up and to my interest/curiosity I found this RAM (CAMM) in it.

its a very interesting design. What I do find interesting is that there is no extra slot for more ram. so if /when i decide i want more than the 16GB I need to remove the existing. which is only slightly better than soldered ram in my opinion.

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In my experience most laptops that did have more than one slot would usually have both filled with smaller modules from the factory in order to use two lanes instead of one, so you would need to remove the existing memory to upgrade anyway. Also, if there standard catches on it should be much easier to buy modules.

If RAM comes loose often enough that support paper mentions it, it's not a good sign.

Too bad they didn't solder it in place.

Perhaps they should do the same with ssd memory too, just in case.

Thats already the case with tablets

And MacBooks.

Surface line has replaceable SSDs. On the newer Pros it's super easy to access too, just a sim eject tool. My Surface Pro X is basically the same thickness as my 2017 iPad Pro as well so it's not even something that requires really thick devices. I think it's fantastic and wish more had it.

So specifically, the problem here is that the contacts are made by tiny spring connectors on the motherboard. They 'spring' a distance of about 0.2 mm - which accounts for bending or flexing of each board. However, if the screws aren't tight, then perhaps 0.1mm of your 0.2mm range is wasted, and the RAM might work until the motherboard is bent or flexed and then it'll stop working.

End result: You have a laptop that crashes whenever you pick it up from the 'wrong' corner.

The CAMM socket has an 128-bit/144-bit interface, so it is equivalent with 2 SODIMM sockets.

Even if with 2 SODIMM sockets you could populate or upgrade only 1 socket, the performance could be much worse than when using and replacing a matched pair of modules.

I have never used mismatched memory modules and many others do likewise, so if you want the best performance it does not matter that there is a single CAMM socket, it just makes the replacement simpler.

For laptops with two DIMM slots you would usually want both populated anyways for dual-channel ram speeds. CAMM does dual channel with one module.

I'm wondering whether amd or intel will match apple on a future platform, who have been using 4 or more channels in their newer macbooks.

My Dell Precision 7750 came with 8GB but I was able to upgrade it to 128GB with cheaper after-market RAM. There were two RAM slots on the front of the motherboard and two more on the other side, which required me removing the keyboard to access.

> its a very interesting design. What I do find interesting is that there is no extra slot for more ram. so if /when i decide i want more than the 16GB I need to remove the existing. which is only slightly better than soldered ram in my opinion.

Changing only the memory vs changing the whole laptop with battery, motherboard (incl. CPU/GPU), display, chassis seems at least an order of magnitude better. It was maybe meant hyperbolic, but I want to make clear that having the option to replace memory is really a lot better than soldered memory.

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