Lower density chips are cheaper, because they can be made in previous generation fabs churning out previous generation wafers with previous generation equipment. So there isn't a choice between making a high or low density wafer from the same fab line.
Are there any older generation fabs making DDR5-6400 like the article discusses? As far as I know those ones were mostly upgraded to newer processes and the long lifecycle fabs have targeted slower speeds.
It wouldn't make sense to throw the previous gen machinery to the trash if it can keep making profitable memory. Esp as smaller module capacities become more common now with the price increases. You need to update the chip design for DDR4 -> DDR5 but there's no magic flashy business in DDR5 meaning it could only be implemented in the latest process node.
Is there all that much using larger node sizes for new RAM?
Or is it just binning by defects, the lower sized parts are just the full size but with defects disabling large chunks of the silicon as I would expect?
