Comments by "shazmosushi" (@shazmosushi) on "China’s Next Semiconductor Giant: Yangtze Memory" video.

  1. Flash memory prices have remained stubbornly high for a long time. The incumbent manufacturers have not been innovating. It's crazy to me that mechanical hard drives remain better on a dollar per terabyte basis. Consider that a tiny MicroSD card is available in 1 terabyte capacity. And of that MicroSD card only a small amount of its area is dedicated to the flash memory itself, the rest is dedicated to the physical connector pins, the controller and the casing. There's no reason why a 2.5" laptop hard drive couldn't contain hundreds (even thousands) of terabytes of flash memory. It's just a matter of being able to cheaply manufacture enough silicon. Heat dissipation is not a problem if the memory access patterns are slow enough (at the extreme, Amazon Glacier type workloads). I feel like there's a big market opportunity for a company to figure out a way to manufacture MUCH higher capacity hard drives. The entrance of Yangtze Memory may spur this on.
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  2. ​ @shakingwater  Yes and no: the reasons NVMe solid-state drives tend to be faster than MicroSD cards are because solid-state drives have multiple flash chips being written to in parallel with a much larger thermal envelope (with higher performance drives including a heat sink), and they have a much larger bus (eg 4 lanes of PCIe 3.0). The NAND flash memory is otherwise exactly the same. Though as you may know "part binning" will mean typical MicroSD card tend to get flash memory with more factory defects, with the built-in controller chip on both solid-state drives and MicroSD cards transparently marking bad sectors, handing wear leveling and doing error correction. Designing the circuit boards that can transfer the data very fast without data errors is not a show stopper, and lanes of PCI Express scales pretty linearly (eg, 16 lanes of PCIe 4.0 provides 32 GByte/s). The proposed device is the size of a 2.5" laptop hard drive, so signal integrity issues at high data rates over such short distances shouldn't be a big problem. But as mentioned, trading slow transfer rates for extremely high capacity is acceptable for many workloads (at an extreme, see Amazon Glacier). I think the only show stopper to the 2.5" laptop hard drives storing hundreds (even thousands) of terabytes of flash memory is figuring out a way to manufacture the huge amount of silicon required at much lower prices. Hopefully the entrance of companies like Yangtze Memory spurs this on.
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  3. 4:37 It's interesting how different the world was in 2008 (the year of the Beijing Olympics). I can't imagine it being politically feasible for AMD and Fujitsu to transfer advanced manufacturing knowledge to China these days. These days in political circles it's more widely recognized that the skills Yangtze gains from manufacturing lower value semiconductors will eventually be used to move up the value chain, and crucially that China (unlike South Korea or Taiwan) is not going to become more open as it grows richer. Like it or not, this view means that policy makers see China moving up the value chain as undesired outcome, something that should be blocked with policy and sanctions. I suspect that NAND manufacturing tech transfer would have been blocked if it was 2021.
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  4. The "ASML: TSMC's Critical Supplier, Explained" goes into sanctions and the international suppliers chain: https://www.youtube.com/watch?v=CFsn1CUyXWs Also checkout the multiple videos on this channel on SMIC and HiSilicon for more coverage.
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