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threecheeseyesterday at 9:10 PM2 repliesview on HN

Thanks for that, just went down an interesting rabbit hole. Many of us were hoping this re-tooling would eventually trickle some fast RAM down to DRAM-exhausted PCs, but given it would require a rearchitecture of the motherboard it's unlikely.


Replies

craigjbtoday at 12:44 AM

HBM4 has over 2048 signals to the processor’s PHY with tight signal integrity requirements that require the HBM stack to be < 0.5 mm from the processor die. That’s why HBM integration is done with interposers (soldered on the package). So, it’d be the CPU package that integrates it. Motherboard is too far away.

srousseyyesterday at 10:37 PM

HBM also trades bandwidth for latency, and your regular computing is much more sensitive to latency than bandwidth.