Re: Persistent memory has been failing in the market for decades
> The question really is why bloody servers? Between grid reliability and UPS persistent memory has limited utility.
That is very true.
The gap may be for something that's not quite as fast as DRAM but much cheaper - it doesn't need to be non-volatile. Then having 1TB in-RAM databases would become much more feasible.
Besides, you can always turn a volatile memory into a non-volatile one by adding a battery backup, or by dumping the contents periodically to persistent storage: witness laptop suspend and hibernate.
Now, the gap in price per GB between SSD and DRAM is perhaps 10-15x, so this is still a pretty tight niche to fit into. Would I want a laptop with 16GB of full-speed DRAM and 64GB of slower secondary RAM, if I could instead have an extra 256GB SSD for the same price as the slower RAM? Probably not. For a database server? Possibly.
The same applies to Xpoint. Given a choice between 128GB of Xpoint or 512GB of SSD, I think most people would take the SSD. It would only be very specific heavy transaction workloads which would benefit enough from the Xpoint to make the extra cost worthwhile.
