OTOH, new HPC systems have been quick to adopt Zen in the form of dual-socket EPYC nodes.

Actually if you look at the current top 10 supercomputers, only 2 are Intel. The rest are custom ARM or RISC CPUs (in Japan and China), IBM Power9, or AMD EPYC.

My take at this is because of inertia. I have a large fleet of servers that have been Intel since forever. I see no reason to migrate them today as things work reasonably well. We upgrade the hardware every 4-5 years. So during the next upgrade for sure I'll choose AMD, there is no question of that. ARM will be a serious competitor and RISC-V, too, that's for sure - but they are just not there yet when we talk about maximum performance (in our case, energy consumption is not the main concern)

I think this is largely just lag between orders for new xen parts and the capacity coming online. I would expect to see a lot of xen processors in fleets being built today.

>the server market was relatively slow to adopt Zen.

Is this finally an accepted truth now? I have been banging on about it for years that AMD are not doing good enough on Server. They will still gain a little more market share with Zen 4, but now Intel is coming back. The perfect opportunity windows is closing down.

AMD doesn't have any product to go around. And this was true even before covid.

I was thinking about the fact that more and more companies are renting compute from e.g. AWS - so for them switching to a different architecture can be as easy as changing a single parameter in a config file, if the cloud provider offers it a bit cheaper.