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Is the problem truly down to physics or is it down to the stovepiped and conservative attitudes of PC part manufacturers and their trade groups like JEDEC? (Not

Is the problem truly down to physics or is it down to the stovepiped and conservative attitudes of PC part manufacturers and their trade groups like JEDEC? (Not that consumers don't play a role here too). The only essential part of sockets vs solder is the metal-metal contacts. The size of the modules and the distance from the CPU/GPU are all adjustable parameters if the will exists to change them.

throw-qqqqq 1y ago
> The only essential part of sockets vs solder is the metal-metal contacts And at GHz speeds that matters more than you may think.
topspin 1y ago
> Is the problem truly down to physics Yes. The "conservative attitudes" of JEDEC et al. are a consequence of physics and the capabilities of every party involved in dealing with it, from the RAM chip fabricators and PCB manufacturers, all the way to you, the consumer, and the price you're willing to pay for motherboards, power supplies, memory controllers, and yield costs incurred trying to build all of this stuff, such that you can sort by price, mail order some likely untested combination of affordable components and stick them together with a fair chance that it will all "work" within the power consumption envelope, thermal envelope, and failure rate you're likely to tolerate. Every iteration of the standards is another attempt to strike the right balance all the way up and down this chain, and at the root of everything is the physics of signal integrity, power consumption, thermals and component reliability.
- kbolino 1y ago
  As I said, consumers play a part here too. But I don't see the causal line from the physics to the stagnation, stovepiping, artificial market segmentation, and cartelization we see in the computer component industries. Soldering RAM has always been around and it has its benefits. I'm not convinced of its necessity however. We're just now getting a new memory socket form factor but the need was emerging a decade ago.
jmb99 1y ago
> The only essential part of sockets vs solder is the metal-metal contacts. Yeah... And that’s a pretty damn big difference. A connector is always going to result in worse signal integrity than a high-quality solder joint in the real world.
- kbolino 1y ago
  Is that really the long pole in the tent, though? No doubt the most tightly integrated package can outperform a looser collection of components. But if we could shorten the distances, tighten the tolerances, and have the IC companies work on improving the whole landscape instead of just narrow, disjointed pieces slowly one at a time, then would the unsoldered connections still cause a massive performance loss or just a minor one?
  - numpad0 1y ago
    Yes. Signal integrity is so finicky at frequencies DRAM operates that whether you drill the plated holes on boards that complete the circuit to go completely through the board or stop it halfway starts to matter due to signals permeating into the stubs of the holes and reflecting back into the trace causing interference. Adding a connector between RAM and CPU is like extending that long pole in the tent in the middle by inserting a stack of elephant into what is already shaped like an engine crankshaft found in a crashed wreck of a car. Besides, no one strictly need mid-life upgradable RAMs. You're just wanting to be able to upgrade RAM later after purchase because it's cheaper upfront and also because it leaves less room for supply side for price gouging. Those aren't technical reasons you can't option a 2TB RAM on purchase and be done for 10 years.
    - kbolino 1y ago
      In the past, at least, RAM upgrades weren't just about filling in the slots you couldn't afford to fill on day one. RAM modules also got denser and faster over time too. This meant you could add more and better RAM to your system after waiting a couple years than it was even physically possible to install upfront. Part of the reason I have doubts about the physical necessity here is because PCI Express (x16) is roughly keeping up with GDDR in terms of bandwidth. Of course they are not completely apples-to-apples comparable, but it proves at least that it's possible to have a high-bandwidth unsoldered interface. I will admit though that what I can find indicates that signal integrity is the biggest issue each new generation of PCIe has to overcome. It's possible that the best solution for discrete PC components will be to move what we today call RAM onto the CPU package (which is also very likely to become a CPU+GPU package) and then keep PCIe x16 around to provide another tier of fast but upgradeable storage.

throw-qqqqq 1y ago

> The only essential part of sockets vs solder is the metal-metal contacts And at GHz speeds that matters more than you may think.

topspin 1y ago

> Is the problem truly down to physics Yes. The "conservative attitudes" of JEDEC et al. are a consequence of physics and the capabilities of every party involved in dealing with it, from the RAM chip fabricators and PCB manufacturers, all the way to you, the consumer, and the price you're willing to pay for motherboards, power supplies, memory controllers, and yield costs incurred trying to build all of this stuff, such that you can sort by price, mail order some likely untested combination of affordable components and stick them together with a fair chance that it will all "work" within the power consumption envelope, thermal envelope, and failure rate you're likely to tolerate. Every iteration of the standards is another attempt to strike the right balance all the way up and down this chain, and at the root of everything is the physics of signal integrity, power consumption, thermals and component reliability.

kbolino 1y ago
As I said, consumers play a part here too. But I don't see the causal line from the physics to the stagnation, stovepiping, artificial market segmentation, and cartelization we see in the computer component industries. Soldering RAM has always been around and it has its benefits. I'm not convinced of its necessity however. We're just now getting a new memory socket form factor but the need was emerging a decade ago.

jmb99 1y ago

> The only essential part of sockets vs solder is the metal-metal contacts. Yeah... And that’s a pretty damn big difference. A connector is always going to result in worse signal integrity than a high-quality solder joint in the real world.

kbolino 1y ago
Is that really the long pole in the tent, though? No doubt the most tightly integrated package can outperform a looser collection of components. But if we could shorten the distances, tighten the tolerances, and have the IC companies work on improving the whole landscape instead of just narrow, disjointed pieces slowly one at a time, then would the unsoldered connections still cause a massive performance loss or just a minor one?
- numpad0 1y ago
  Yes. Signal integrity is so finicky at frequencies DRAM operates that whether you drill the plated holes on boards that complete the circuit to go completely through the board or stop it halfway starts to matter due to signals permeating into the stubs of the holes and reflecting back into the trace causing interference. Adding a connector between RAM and CPU is like extending that long pole in the tent in the middle by inserting a stack of elephant into what is already shaped like an engine crankshaft found in a crashed wreck of a car. Besides, no one strictly need mid-life upgradable RAMs. You're just wanting to be able to upgrade RAM later after purchase because it's cheaper upfront and also because it leaves less room for supply side for price gouging. Those aren't technical reasons you can't option a 2TB RAM on purchase and be done for 10 years.
  - kbolino 1y ago
    In the past, at least, RAM upgrades weren't just about filling in the slots you couldn't afford to fill on day one. RAM modules also got denser and faster over time too. This meant you could add more and better RAM to your system after waiting a couple years than it was even physically possible to install upfront. Part of the reason I have doubts about the physical necessity here is because PCI Express (x16) is roughly keeping up with GDDR in terms of bandwidth. Of course they are not completely apples-to-apples comparable, but it proves at least that it's possible to have a high-bandwidth unsoldered interface. I will admit though that what I can find indicates that signal integrity is the biggest issue each new generation of PCIe has to overcome. It's possible that the best solution for discrete PC components will be to move what we today call RAM onto the CPU package (which is also very likely to become a CPU+GPU package) and then keep PCIe x16 around to provide another tier of fast but upgradeable storage.