“I’ve been saving for months to get the Corsair Dominator 64GB CL30 kit,” one beleagured PC builder wrote on Reddit. “It was about $280 when I looked,” said u/RaidriarT, “Fast forward today on PCPartPicker, they want $547 for the same kit? A nearly 100% increase in a couple months?”
…Is it that interchangeable?
TBH I know little of memory fabs and HBM ICs, but I know (say) TSMC can’t just switch from a power-optimized process to a high frequency one at the drop of a hat.
Slightly different part, same process. The bigger bottleneck is packaging - HBM is 3d stacked.
Ah. Yeah. And its on the fab to do that.
I always though it’d be cool for CPUs to switch to packaged RAM, too. Samsung apparently tried to do it with Wide I/O for mobile ARM stuff, but it never caught on.
If I’m following what you mean by packaged RAM, Apple does that. It’s fast, but you can’t upgrade it.
That’s (as I understand it) a misconception.
Apple attaches their laptop RAM the same way all smartphones do. It’s a wide bus with LPDDR, which makes it an unusual configuration amongst laptops, but it’s technically conventional. And relatively cheap.
AMD’s Strix Halo chips are the same. Apple could use LPCAMM to make the memory upgradable if they wanted, they just… don’t.
When we talk ‘packaging’, we’re talking putting chips on advanced substrates with denser wires than one could possibly get on a motherboard (or a ‘mini’ motherboard which is kinda what Apple/smartphone RAM is packaged on), stuff silicon fabs have to do:
https://www.tsmc.com/english/dedicatedFoundry/services/advanced-packaging
And HBM falls into this bucket. The way its hooked up to the processor is physically different than PC RAM sticks, or Apple’s RAM. This is mostly not done on consumer stuff because its very expensive, and most of TSMC’s advanced packaging production capacity is reserved for server stuff.