alt Hacker NewsDifferent types of DRAM can literally be made from the same already-etched wafer. The DRAM bits themselves don't change at all. What's different between DDR4, DDR5, and HBM is the IO interface to the chip. Changing this does not require significant retooling or relearning.
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youarentrightjr • today at 1:25 AM
> The DRAM bits themselves don't change at all. What's different between DDR4, DDR5, and HBM is the IO interface
That's not completely accurate - since the bw between these are different, the routing and therefore propagation delays for DDR4 won't allow it to magically be used as DDR5 or HBM.
If you design for the most strict timings, then sure.
pdhborges • yesterday at 10:39 PM
Does that mean CXMT is one inch away from also eating into the DDR5 market?
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> Different types of DRAM can literally be made from the same already-etched wafer.
The assumption here is that you would stop making DDR5 but continue to make DDR4 so that you could start making DDR5 again without too much trouble. But the older chips have even lower margins than the newer ones. Most of the fabs and equipment for making DDR4 were created when it was current and then they stay in operation as long as there is still enough demand for it.
If you don't make DDR5 and DDR6, what happens to your DDR4 fabs when DDR4 is where DDR2 is now? They close because nobody wants it anymore. And then you're not trying to get to DDR6 from DDR4, you're trying to get to DDR6 from an empty desert.