They're also really high latency, unless ridiculous-amounts-of-ram server technology has gotten better in the past few years.

Here's one I found that supports up to 48 TB:

https://www.hpe.com/us/en/product-catalog/servers/integrity-...

They don't include a price, so I'd assume it's in the low millions or high six figures.

The latency doesn't sound that bad. It's 200ns to access memory on another local NUMA node, and 500ns to access memory on another machine using NUMAlink.

Fascinating tech. I had no idea this could be done with Xeons.