Comment by jcranmer

Processing in memory was one of the extra topics we covered in my grad computer architecture class. Fifteen years ago. And even then, it was very clearly an old-hat idea.

One of the problems with trying to move a lot of ALUs close to the DRAM logic is that ALUs are pretty hot, and DRAM is some of the most sensitive components to heat. There are some other issues too, like the process manufacturing differences mentioned by a sibling comment.