[emn13]

Nand flash is pretty dense, but way too slow. Sram is fast but not at all dense, needing 6 transistors per bit.

For reference: https://en.m.wikipedia.org/wiki/Transistor_count lists all the largest cpu as of 2019 amd's epyc Rome at 39.54 billion MOSFETs, so even if you replaced the entire chip with Sram you wouldn't even quite reach 1GB!

Dram would be enticing, but the details matter.

[chemmail]

Nand is nonvolatile and the tradeoff with that is write cycles. We have an inbetween in the form of 3D Xpoint (Optane), Intel is still trying to figure out the best way to use it. It currently like an L6 cache after system DRAM.

[thu2111]

Well not just Intel. Optane is a new point in the memory hierarchy. That has a lot of implications for how software is designed, it's not something Intel can do all by itself.