Meta reuses old RAM in new servers with custom bridge chip
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Re: Meta reuses old RAM in new servers with custom bridge chip
#2ScholarlyArticle: "Vistara: Making CXL Real—Full Path from ASIC Design and OS Support to Hyperscale Deployment" (2026) https://aisystemcodesign.github.io/papers/isca26/vistara_cam...
TIL there are 2x 2.5GbE PCI-E HAT adapters for Pi 5.
How to attach RAM to the new NVLink/UALink fiber buses?
Re: Meta reuses old RAM in new servers with custom bridge chip
#3The interesting part of this "RAM crisis" is similar to other fields where a problem results multiple parties looking for alternative solutions.
This yields for exciting ideas or workarounds that might result a post-crisis memory boom (hopefully) also for local machines.
1. Lowest, Apple is evaluating new Chinese manufacturer which means change of supply demand if indeed it has reasonable QA. (https://www.ft.com/content/f4ac5c92-03be-4499-b16a-017a7e9ee...)
2. Companies tries to workaround performance - suddenly single channel is 'ok' ? :) (https://www.gigabyte.com/press/news/2403)
Re: Meta reuses old RAM in new servers with custom bridge chip
#4Why not go directly to the source article that has a lot more details?
https://www.theregister.com/systems/2026/06/29/zuck-saves-me...
Re: Meta reuses old RAM in new servers with custom bridge chip
#5Why not go directly to the source article that has a lot more details? https://www.theregister.com/systems/2026/06/29/zuck-saves-me...
> Why not go directly to the source article
Which seems to be the sister site of Register; https://www.blocksandfiles.com/architecture/2026/06/26/panmn...
Re: Meta reuses old RAM in new servers with custom bridge chip
#6The interesting part of this "RAM crisis" is similar to other fields where a problem results multiple parties looking for alternative solutions. This yields for exciting ideas or workarounds that might result a post-crisis memory boom (hopefully) also for local machines. 1. Lowest, Apple is evaluating new Chinese manufacturer which means change of supply demand if indeed it has reasonable QA. ( https://www.ft.com/con…
> suddenly single channel is 'ok'
Single channel RAM surely beats any disk-based swap.
Re: Meta reuses old RAM in new servers with custom bridge chip
#7Why not go directly to the source article that has a lot more details? https://www.theregister.com/systems/2026/06/29/zuck-saves-me...
Source paper linked is https://aisystemcodesign.github.io/papers/isca26/vistara_cam...
From a quick skim, you could think of this as roughly equivalent to shoving a large amount of DDR4 on a PCIe card and using it as a swap space. It's more sophisticated (see CXL protocol), but that gives you an idea of the tradeoffs. It seems there is some OS-level support for moving hot/cold pages between the main fast DRAM and the expansion higher latency DRAM.
It's a very valid point that DRAM has a fairly long lifetime and contains significant embedded carbon emissions, as well as the current availability crisis of new DRAM.
Re: Meta reuses old RAM in new servers with custom bridge chip
#8It’d be nice if there were a consumer version of this. I have plenty of old RAM.
Re: Meta reuses old RAM in new servers with custom bridge chip
#9There are standard product CXL memory expander chips if you don't want to design a custom chip.
Re: Meta reuses old RAM in new servers with custom bridge chip
#10With regards to RAM price I never understood the following: A 16GB RAM stick has 16*8=128 billion bits, with 1 transistor per bit, thats still 128B, yet its supposed to cost like $60 before the price hikes? In contrast, a 5090 GPU was $2000 (true it has RAM, but you're paying for the GPU ASIC really, I guess the rest of the GPU was less than $500), it had 93B transistors.
GPU transistors are smaller due to the more advanced process node (cost per transistor metrics aren't really clear, if they improve on advanced node or not, but I'd say they get cheaper as they get smaller, as technology costs are amortized).
I'm sure both RAM and logic use a process that is quite similar in both inputs and manufacturing steps. So while RAM is a commodity product, this insane price difference didn't make any sense.
So I guess when those fundamental inputs become a constraint, it would make sense for $/transistor move closer for both, which is a massive hike for RAM.