Question Zen 6 Speculation Thread

[basix]

Well, in the end it will be something and not "not anything"

 

[lucasworais]

Jeez, what these speculations threads are turning into

 

[okoroezenwa]

Jeez, what these speculations threads are turning into

Pedantry Inc.

 

[StefanR5R]

(moar cores per socket vs. memory capacity)

Whatever happened to CXL attached RAM? 5th Gen EPYC fully supports the technology and has even partnered with Micron for compatible modules. There's really not a "limit" for total system RAM imposed by the 12-16 channel shoreline limitation, just that you have to pay a smallish price in latency and bandwidth (still massively faster than SSD) for the CXL ram...

CXL memory extenders are CPUs without cores.

Let's undertake a thought experiment: We are a cloud service provider, i.e. our business is to rent out access to virtual machines. We are about to add 102,400 cores to our datacenter. How do we plan to do that? Will we add 400 sockets with 256 cores each, each of them with local memory attached? Or will we rather add 200 sockets with 512 cores and another 200 sockets with 0 cores (all of them with memory attached)?

I imagine that in this business, CXL attached memory will become attractive once it becomes possible at low price and low power consumption to attach memory nodes to more than a single computer. Also, an ability to boot up and shut down these expanders on demand may be desirable.

I am probably not entirely up to date, but the CXL memory expanders which I have seen so far were only for local use within one machine, not to be shared between machines.

 

[igor_kavinski]

I am probably not entirely up to date, but the CXL memory expanders which I have seen so far were only for local use within one machine, not to be shared between machines.

Not an issue if they really want resources shared. We have an old Dell VRTX where blades are inserted into a "mother" chassis and anything plugged into that chassis can be accessed by any of the blade servers. But it's like Nehalem era.

 

[adroc_thurston]

I am probably not entirely up to date, but the CXL memory expanders which I have seen so far were only for local use within one machine, not to be shared between machines.

Because memory pooling is a 2.0 thing (3.0, really, 2.0 mempools never quite worked right).