However, the thermal simulations reveal severe challenges for the 3D HBM-on-GPU design.

Imec presented an examination of a 3D HBM-on-GPU design aimed at increasing compute density for demanding AI workloads at the 2025 IEEE International Electron Devices Meeting (IEDM).

The thermal system-technology co-optimization approach places four high-bandwidth memory stacks directly above a GPU through microbump connections.

Each stack consists of twelve hybrid-bonded DRAM dies, and cooling is applied on top of the HBMs.

Thermal mitigation attempts and performance trade-offs

The solution applies power maps derived from industry-relevant workloads to test how ...