imec and Vrije Universiteit Brussels Model: GPU 3D Packaging Expansion Implies Embodied Emissions Increase 52 Percentage Points Lower Than 2.5D
A team from imec and Vrije Universiteit Brussels used the netzero modeling platform to estimate the embodied emissions of chiplet-based GPUs under 2.5D and 3D scaling scenarios. With compute units and High Bandwidth Memory (HBM) capacity doubled, the embodied emissions increase for 3D scaling was 89%, compared to 141% for 2.5D; the research team thus positions 3D stacking as an attractive solution for limiting the embodied emissions associated with GPU expansion. These results come from a preprint paper and represent modeling estimates rather than independent measurements.
AI computing power demand continues to grow, and carbon emissions from hyperscale data centers are receiving increasing attention. While operational energy consumption is the most discussed aspect, the energy and materials consumed during chip manufacturing itself—known as embodied emissions—also constitute a significant environmental cost. As GPUs transition from single chips to chiplet architectures and scale computing power through 2.5D or 3D packaging, there has previously been a lack of quantitative comparison regarding the differences in embodied emissions between these packaging routes.
Researchers from imec and Vrije Universiteit Brussels filled this gap in a preprint paper released in October 2026. Using imec’s netzero modeling platform, they modeled a chiplet-based GPU scaled in both 2.5D and 3D configurations, doubling the number of compute units and HBM capacity, and then estimated the increase in embodied emissions for both approaches.
The modeling results show that the embodied emissions increase for 3D scaling is 89%, while for 2.5D scaling it is 141%. Based on this, the research team positions 3D stacking as an attractive solution for limiting the embodied emissions brought about by GPU expansion.