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Comment by corvettez0606 | Hacker News Reader

Apple did a lot right with this change to make memory fast. I can see AMD and Intel adopting a similar strategy and putting something like 16 GB of dram on chip. Need more than that? Then add “L2 dram” on an external dimm. 16 GB will cover most people’s use cases and with the ability to add L2 dram the high memory usage cases are covered too. (I remember when you could buy cards with L2 cache on them back in the day. 486 I think had them. This is just taking it to the next level.)

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Not an Apple innovation.

Intel already launched a processor with 16GB on-package MCDRAM in 2016 (Knight's Landing Xeon Phi). You can even buy an Intel Xeon with 64GB HBM2 today. Nvidia likewise has been packaging HBM with their server GPUs.

Embedded DRAM (eDRAM) been used for long time in the mobile and console space. e.g. IBM's POWER7 (e.g. Nintendo Gamecube) and Intel Haswell products. However, using a logic process node to make DRAM cells is wasteful. Packaging technologies have advanced sufficiently that you now regularly see regular DRAM dies (LPDDR, HBM) being put on-package.

But all of that is packaging and manufacturing technologies. We're still taking to DRAM over a memory bus like we're still living in the '80s. The true innovation I'm looking out for is for a company to stick its neck out and use a different communication standard to talk with the DRAM modules. Something like the CLX.mem standard, which is used in the server space to talk to memory expansion modules.

"16GB will cover most people's use cases" may be true, but DIMMs will also cover most people's performance needs.

The amount of people that need memory speeds and latencies beyond what SO-DIMM and CAMM can handle, but only need 16GB of RAM is absolutely tiny.

And when it ceases to be sufficient, just discard it and purchase a replacement. How convenient.

Maybe for ultrabooks and similar but I'm not overly thrilled about the idea.

Is there a good overview of how much of a benefit the onchip ram is?

All modem CPUs have L1, L2, and L3 caches. Commonly available consumer chips go up to 144MB already.

Parent is not speaking about cache (L1/L2/L3/...), but about main memory (RAM) of which 16GB would be permanently integrated into the CPU - this would be L1 RAM and of the rest, L2 RAM which would be outside of CPU.

I’m not exactly sure why they mentioned it, but in their defense—it is all fundamentally volatile storage, just used differently. Memory of course has a special magical meaning to operating systems, but hypothetically it might make sense to mark L3 cache as memory, and maybe… treat DRAM as swap? Hypothetically!

"L3 cache" is a cache of what then? (SWAP stores only parts of memory, not all...)

It wouldn’t be a cache anymore in that case. The hardware thing is named after the typical job we have for it, but if we want to play with the idea of changing how things are used the names might not line up perfectly anymore.

It’s all volatile storage with different uses.

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