below problem e.g.
1. Development costs exceed $100M, making it inefficient.
2. The base die cannot be made compatible with the core dies of the three memory companies.
3. Insufficient capabilities.(amd, I didn’t say that.)
4. Custom HBM starts with HBM4e (Samsung and Hynix have created dedicated custom HBM teams)
5. Possibility – Dualization of core die. (aka c-die) problem of stock
