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by fh973 2882 days ago
While there are some analytics workloads that will benefit tremendously, the main use case will be improving server utilization.

Currently RAM is not a compressible resource like CPU. However many applications don't have a fixed or if easily predictable RAM footprint and so you have to overprovision. Swap has been there to solve that but with its performance impact, it often can't be used for server applications.

These DIMMs will blur the boundary between memory and swap and make swap again viable.

2 comments

I dont get your logic. CPUs have a finite number of instructions they can do in a timeframe, its not compressible. In the other one someone could compress the memory, works great for storage. Sure, it‘ll be slower but compressing seldomly used memory pages like macOS does is indeed possible
I think his point is that you can "run" a large amount of applications at the same time on a CPU. It will execute everything, albeit slowly. This might not be acceptable for performance concerns, but it's doable.

He's not talking about actual data compression in RAM. Because even with compression, with current OSes, if you try to fit more than 20GB of data, let's say becoming 10GB compressed, into 5GB of RAM, it's not possible. You have to swap and at that point your performance is completely gone.

The performance gap between an overloaded CPU and swapping is humongous. One is annoying or slightly troublesome, the second is a death knell.

> and make swap again viable

You shouldn't work in political marketing :-)