Vertical DRAM Stacking Expands Thermal Design Space Beyond HBM-on-GPU
imec researchers highlight how 3D DRAM stacking could ease thermal bottlenecks in future GPU memory architectures, offering new degrees of freedom in thermal design.
Rethinking Memory Thermal Limits
As high-bandwidth memory (HBM) stacks continue to scale in density and bandwidth—with HBM4 adoption expected to ramp in 2026—thermal management has become a critical constraint in GPU-based AI systems. Imec's recent work suggests that vertically stacking DRAM in new configurations could expand the thermal design space beyond conventional HBM-on-GPU approaches.
Key Insights from imec
The research points to vertical DRAM stacking as a pathway to improve thermal performance while maintaining high bandwidth. By decoupling the location and arrangement of DRAM layers from the GPU die, designers gain more flexibility in dissipating heat and managing thermal gradients. This could be particularly relevant as AI accelerators push power envelopes higher in 2026 and beyond.
Implications for Future Architectures
With the industry moving toward more complex 3D integration schemes, imec's findings suggest that thermal design will need to evolve alongside memory architectures. Vertical stacking of DRAM may offer a complementary approach to HBM, enabling more efficient thermal management in next-generation AI and HPC systems.
Note: This article is based on an imec presentation and does not include specific technical details from the original source.